Booji Boy is the closest thing to a mascot DEVO has; he is a fictional character represented by Mark in a mask and described as "the spirit of infantile de-evolution". In concerts, Booji Boy would typically sing the last encore.
His father, General Boy, was the leader of the De-Evolutionary Army. His mother appears in an important role at the end of the home video game Adventures of the Smart Patrol .
Booji Boy, in DEVO fiction (as described in My Struggle), is the frontman of DEVO. Although usually very nice to his audience (almost always closing an appearance with a speech about how great they've been), he is extremely pessimistic and even regards his birth as one of the worst moments of his life. He looks forward to the day when "normal" humans go extinct, often urging his followers to forcibly modify their DNA and then "kill all the normal people". (He abandoned these speeches after 1979 , possibly due to brain damage (see below).
Although he is mysteriously mature (and very tall), he usually resides in a crib. The mask most see is not, in fact, the true form of Booji; few have seen him exposed. The Chinaman describes him as a handsome black-haired German man who has serious vision problems.
He worked alongside DEVO in the factory and performed with them in the club.
He was the courier of papers from the Chinaman to General Boy.
He was bound to a chair and stabbed in the abdomen by Gorj.
He is surprisingly irresponsible, often getting himself into extremely bad situations (sometimes due to the lack of oversight by General Boy). In 1978, he made the bad decision of sticking a fork into an operational toaster placed dangerously close to his crib. According to Redeye Express, he suffered from sugar and caffeine addiction.
In 1979 he performed at some concerts with DOVE, the band of love.
In 1980, he placed his own head inside of a hydraulic press despite a clear warning from the General. (For all of 1980, his face was severely damaged.) Although he seemed to recover the next year, in 1982 he apparently began chewing on the remaining wounds; this resulted in wearing a cone-shaped anti-biting collar.
In 2006, he was beheaded by Osama Bin Laden, though even that has been unable to keep him down, because he returned in 2007 for DEVO's European tour, continuing thereafter to appear in concert to the present.
In 2010 he appeared in a video short urging spuds to reject the focus group blue domes. He wears his choir boy robe backwards and his mouth works. [*]
An excited Booji spread the "GOOD NEWS" about HARDCORE DEVO Tour 2014 using a microphone and video toys supplied by DEVO. 
He has continued to appear at DEVO festival shows post-HARDCORE Tour.
Booji appears more corpulent in the 21st century.
He can play a keyboard, although he is usually limited to very simple tunes performed on a child's toy synth.
Booji Boy came into existence when Mark saw a strange-looking baby mask in a costume store in 1975. He was one of DEVO's costumes through the very early years, and is the only surviving alter-ego after they abandoned the concept. He became a regular appearance at DEVO shows until 1988, singing the last encores. (In 1980, his "crushed face" was created by inverting a mask and smearing it with Vaseline.) Also in 1980, he was interviewed on the Dr. Demento radio show, where he selected several tracks that were played. 
He went missing in 1989 to make room for the accommodation of DEVO's full-size discography. In the late-90s comeback tours, despite their retrospective "early years" setlist, he only appeared at the comeback Sundance Festival show known as "Butch DEVO and the Sundance Gig". According to a fan who asked Mark about Booji's absence, he simply didn't feel like going onstage and being Booji at his age. The lack of Booji masks (which had begun to deteriorate severely) also contributed to this.
In 2004, Booji returned sporting a new mask (all originals were lost or falling apart and no identical ones were available). Booji was "beheaded" in 2006 by Osama Bin laden, and Beautiful World was sung by Jihad Jerry, however Booji returned in a replica mask for the 2007 European tour.
In 2010, "A Message From Booji Boy" 30 second short was made to tie in to the SFE color study but was unused. (Booji wore the same oval glasses live in 2009, including the 2009-11-09 show. This promo was taped before Mark lost his wedding ring at the Minnesota Zoo.)
In 2014 Booji appeared in four short videos on the internet, proselytizing to spuds about DEVO's upcoming Hardcore Tour.
In 2018, before the official release of their two-volume book, DEVO performed once live at the Burger Booglaloo festival. Mark said John Waters persuaded him to appear with DEVO again.
In 2019, DEVO performed one show at the Desert Daze festival in Lake Perris, California. The October 12th show was Mark's last appearance as Booji to date.
According to a September, 2017 article Mark's Booji Boy masks are now "melted" and their "final remains" repose in a plastic bin at Mutato Muzika.
Mothersbaugh, as Booji Boy, wrote a book entitled My Struggle. The title is a satire of Mein Kampf and the book featured a small red leather cover as a poke at Chairman Mao Zedong's "little red book". My Struggle is no longer in print but can be downloaded online.   Excerpts from the book can also be found hidden in Devo's CD-ROM game "Adventures of the Smart Patrol."
In 1975, DEVO apparently obtained a huge amount of Booji masks which lasted them until '88. (Some were damaged intentionally in 1980 for the "severe injury" act.) In the 90s, they began to deteriorate and were unusable live. In 2004, alternate masks that somewhat resembled Booji were obtained, and a more accurate reproduction was made for the 2007 European tour.
Currently, Booji Boy masked are produced by "SikRik Masks in Akron,Ohio under the supervision of DEVO, Inc. and Booji Boy. This is the 2nd Version Sculpt Circa 2014. First Version was in a limited edition of 100 and sold out in 2012. Each original mask design is hand sculpted, hand molded, hand poured, hand trimmed and hand painted by SikRik Studios." Some fans wear them often.
- In the early days, Booji simply wore whatever the band was wearing. Before DEVO standardized their look, photos show Booji in a "Reverse Evolution" tank top and basketball shorts. In time, Booji's outfit changed to a more unique item. From 1988 on, with few exceptions, Booji has worn a choir boy robe.
- a partial list of some outfits and shows:
- 1975-04-04 "Boogie Boy, China Man, Jungle Jim, & The Clown" perform before two consecutive showings of the film "Pink Flamingos" directed by John Waters. 
- 1975-09-31 "Booji Boy, The Clown, Jungle Jim and The Chinaman"  wore blue worksuits at the WHK Auditorium (WMMS-FM Halloween Party), Cleveland, OH 
- Blue worksuit.
- Silver metallic jumper accessorized with a folding crib.
- 1977-08-03 - White suspenders with high waisted white Gurkha shorts.
- 1978 - Standard DEVO black undersuit (athletic shorts and T-shirt) with elbow and knee pads.
- 1978-10-10 - White suspenders with high waisted white Gurkha shorts.
- 1980 - Dark green raincoat (mask inverted)
- 1981 - Plaid synthetic jumpsuit from "Beautiful World" video
- 1982 - Floor-length tunic made from "Floating Spuds" shirt fabric, inverted Spudring worn as collar
- 1988-89 - Yellow and black choir boy robe with "Booji Boy" embroidered on front
- 1996-01-26 - Yellow and black choir boy robe with "Booji Boy" embroidered on front 
- 1996-present - White and purple choir boy robe with orange "Booji Boy" embroidered on back
- European tour - Gaudy "Veezo wear" short-sleeved shirt and shorts outfit with rows of yellow and red dots, with matching brimmed cap. Also worn at the 2007-10-12 non-DEVO performance, with dark slippers and white athletic socks with black and orange bands.
- Skull and crossbones baseball hat. A red baseball hat with a silver glitter skull and cross bones on the front and brim and another on the back. Worn at various concerts 2008 to 2010.
- 2009-11-09 - The white and purple robe, oval glasses, and skull and crossbones baseball hat. Still attached to the hat's side is the store's anti-theft device.
- August, September - Red brimless peaked hat with yellow feather, translucent green framed glasses, black and white "(praying) hands club" oversize sequined T-shirt, green plaid shorts, short black socks, white slippers. T-shirt has large mirrored letters D E V O hung on the back.
- 2011-03-20 - Faux fur white hooded robe with internal lights and red outline of "heart" symbol on the back. Made by The King's Light Up Coats & Royal Robes See photo by Rachel Lee
- 2011-06-16 - Gaudy short-sleeved shirt and shorts outfit with stripes of black, beige, and off-white dots. Pink slip-on shoes with white spots and rolled-down black socks.
- 2012-05-13 - White-framed glasses, T-shirt with airbrushed anthropomorphic unicorn on front, black shorts.
- Australia/New Zealand tour - "CHIMP MURCH" altered T-shirt, worn for about 3 shows in December 2012 .
- HARD CORE DEVO Tour - Booji-sized pink hooded "FOOFA" pajamas with zip-off feet. Officially licensed Yo Gabba Gabba! wear. A black elastic eyeglass holder secures Booji's glasses. Although as old as the hills but as yet unborn, "Booji Boy's Funeral" plays as Booji enters with a 4-wheeled "rollator" walker and then sits on its cargo seat to perform "U Got Me Bugged" solo.
- 2018-06-30 - Booji wears prescription glasses and a fat penguin costume over his custom orange DEVO jumpsuit. It inflates with a small fan. He also generates noise from a circuit bent device in a square yellow cigar box worn suspended from a black strap around his neck. After Jerry sings the first verse, Booji performs "Beautiful World" - for the first time in five years- and then "The Girl Can't Help It", a Little Richard song featured in the film "Pink Flamingos." He also eulogizes the performer Divine, who acted in several John Waters movies.
- 2019-10-12 - Booji wears Mothersbaugh Eyewear reflective frames, a muted pink geometric-pattern short-sleeved button-up shirt, two wristbands on his left wrist (one yellow and one black), and orange pants. He uses a modified blue Jupiter T device attached to a black strap around his neck to perform a mutated synth solo. After Jerry sings the first verse, Booji emerges from the side of the stage to finish "Beautiful World." He then reveals a "RIPBOB2" license plate worn around his waist as well as a black fanny pack full of bouncy balls, which he throws at the audience.
- Booji also has been seen in a silver metallic suit at some '70s performances, in the music video for (I Can't Get No) Satisfaction, and in the Tunnel of Life film.
- Smart Patrol (1974)
- Tater Tot (Lost At Home) (1974)
- U Got Me Bugged (1970s - including 1979, 1996) (2007-10-12 without DEVO) (2014)
- The Words Get Stuck In My Throat (1977 - 1978)
- Booji Needs A Chick (1977)
- Red-Eye Express (1978)
- In Heaven Everything Is Fine (1978 -1979)
- The One That Gets Away (1979)
- Gotta Serve Somebody (1979)
- Tunnel of Life (1980)
- Booji's Beautiful World (1981, 1982, 1988, 1996, 2004, 2007, 2008, 2009, 2010, 2011, 2012, 2013), (2018, 2019) co-vocalist
- Hey Hey My My (1979)
- How Many Ropes (1979 /1982 / 2014)
- Speed Racer (demo) (1982) co-vocalist
- Puppet Boy (1984) co-vocalist
- Somewhere With DEVO (Studio Version Demo) (1988) co-vocalist
- The Girl Can't Help It (2018)
- The Beginning Was The End: The Truth About De-Evolution (short film) (1976)
- (I Can't Get No) Satisfaction (music video) (1978)
- Roll Out the Barrel (1979) 1981 release
- The Men Who Make the Music (1979)
- Tunnel of Life (in-concert film) (1980)
- Beautiful World (music video) (1981)
- Post Post-Modern Man (Rocky Schenck Remix) (music video) (1990)
- 1 second of mask and inset "Satisfaction" clip
- DEVO Live: 1980 (2005)
- Club DEVO (2009 to present). Booji appears in several official performance videos uploaded to ClubDEVO.com by Michael Pilmer.
- Hardcore Devo Live! (2015 documentary with 2014 performance and interviews)
- Human Highway (completed 1982, followed by 4 re-edits) film (w/ DEVO and others)
- The Boogie Boys: You Ain't Fresh (1988) music video (track released 1985)
- Barnes & Barnes: Zabagabee  (1987) in a short tutorial video
- At Safari Sam's, Los Angeles  (2007-10-12) live
- The Adventures of the Smart Patrol (1996) Mac/PC CD-ROM game.
- The "real" name of this version of "Boogie" is "Craig Allen Rothwell."
- Mark recorded the voice.
- Pat Tierney is credited as "Boogie Boy" in the credits reel.
- General Boy is played by Tom Finnegan and Mrs. Rothwell is played by Strawn Bovee and voiced by Josey Roth.
- Credits Reel - YouTube (starts at 0:47")
- "Booji Boy Announces HARDCORE DEVO Tour 2014!" (2014) Online-only promotional videos.
- DEVO @ Twitter.com. DEVO - 29 April 2014 tweet.
- Scribd. "My Struggle Booji Boy" With nonmember preview.
- Dropbox. "mystruggle.pdf" copy of "My Struggle".
- Daily Kent Stater 4 April 1975. Page 9 Advertisements. "DEVO (The De-evolution Band) 'How LOW can you go!' featuring Boogie Boy, China Man, Jungle Jim, & The Clown" KSU library online archive.
- Punk Diary, 1970-1979: The Ultimate Complete Day-By-Day Reference Guide to Punk by George Gimarc (1994). "They come out in their costumes as Booji Boy, The Clown, Jungle Jim and The Chinaman. In the liner notes to the 1992 Ryko CD release 'The Mongoloid Years,' Mark remembers, 'using homemade electronic drums, and a mini-moog, a clavinet, a customized lobotomized Hagstrom guitar, and bass, we proceed to torture stoned urban hippies with 'performance art' way before that label even existed..."
- Devo Live Guide 1973 to 1977
- YouTube. "The Men Who Make the Music" - excerpt. 05/28/79 -Nippon Budokan Hall, Tokyo, Japan.
- YouTube. The Arena, Park City, UT. Beautiful World - Devo / Booji Boy Sundance Film Festival 1996. uploaded by MrSlapyourmammy. Mark wanted this to be DEVO's last show.
- YouTube."Zabagabee: The Best of Barnes & Barnes (1987)" 19:00"-19:45"
- YouTube. "Booji Boy Announces HARDCORE DEVO Tour 2014!" Part 1 of 4.
- YouTube. "Booji Boy Announces HARDCORE DEVO Tour 2014!" Part 2 of 4.
- YouTube. "Booji Boy Announces HARDCORE DEVO Tour 2014!" Part 3 of 4.
- YouTube. "Booji Boy Announces HARDCORE DEVO Tour 2014!" Part 4 of 4.