voice actors O-R
Offerman, Nick See actors N-O
Ukitake et al. on Bleach; Lloyd Asplund on Code Geass; Shobu on Duel Masters; Nanashi on MÄR; Tenma on Monster; Gaara on Naruto (and Naruto Shippuden); Maniwa on Paranoia Agent; Hiroim in Planet Hulk; Nanjiro on The Prince of Tennis; Nightcrawler, Angel, Nitro on Wolverine and the X-Men; etc.
Title character on Axe Cop; Narrator in The Gunfighter; Grandpa Mike in Hotel Transylvania 2; Metalbeard in The Lego Movie; Dr. Klorpins in a couple eps of Son of Zorn.
O'Hara, Catherine See actresses N-O
Victor's mother, Weird Girl, and gym teacher in Frankenweenie; Carlotta in A Monster in Paris; Sally and Shock in The Nightmare Before Christmas; Judith in Where the Wild Things Are; Malicious in Witch's Night Out; etc.
Belle in Beauty and the Beast (and Ralph Breaks the Internet). Also she did an episode of Storytime with...
Wasp on The Avengers: Earth's Mightiest Heroes; Michiru, Nel, Loly on Bleach; Jazz et al. on Danny Phantom; Mimi on Duel Masters 2.0; Yurina on Kekkaishi; Jodi et al. on The Life and Times of Juniper Lee; Ino and Konohamaru on Naruto (and Naruto Shippuden); Suzy on Zatch Bell!; etc.
Oswalt, Patton See comedians
Sockarang on Axe Cop; the title character on Happy!; Professor Dementor on Kim Possible; Quibble Pants in an ep of My Little Pony: Friendship Is Magic; Prince of Whale in an ep of Niko and the Sword of Light; Remy in Ratatouille; etc.
Overall, Park See actresses N-O
Alice Tompkins on The Critic.
Aughra in The Dark Crystal; Fozzie Bear, Miss Piggy, Sam Eagle, Animal, et al. on The Muppet Show (and movies); Bert, Grover, Cookie Monster, Harvey Kneeslapper, et al. on Sesame Street; Yoda in The Empire Strikes Back (and other Star Wars movies); the robot in Zathura; etc.
Jack on MÄR; Red on Pokemon Origins; etc.
Yakko et al. on Animaniacs; Beetle in The Ant Bully; Ditto on Ben 10; Rhomboid Vreedle et al. on Ben 10: Alien Force; Farley in Charlotte's Web 2; Jack et al. on Danny Phantom; Steelbeak on Darkwing Duck; Major Glory et al. on Dexter's Lab; Francois in an episode of Kim Possible; Eric in The Little Mermaid II; Ink Spot and Swifty in The Little Mermaid: Ariel's Beginning; Rev Runner on Loonatics Unleashed; the title character on The Mask; Pinky on Pinky & the Brain; Rude Dog on Rude Dog and the Dweebs; Raphael et al. on the old Teenage Mutant Ninja Turtles; Arthur, Brainchild, the Terror, the Evil Midnight Bomber What Bombs at Midnight, et al. on The Tick; Buck on Time Squad; Bobble in the Tinker Bell movies; and I suppose countless other things.
Hex in the Ben 10 franchise; Ripcord on G.I. Joe: Renegades; Cyborg et al. on Teen Titans and DC Super Hero Girls; Aqualad et al. on Young Justice. Also I saw him in a live-action movie, Dracula II: Ascension.
Perlman, Ron See actors P
Justice on Afro Samurai; Sozin on Avatar: The Last Airbender; Clayface on Batman: The Animated Series; Killer Croc and Bane on The Batman; Xibalba in The Book of Life; Mr. Lancer on Danny Phantom; title character in the Hellboy Animated movies; Shoggoth in Howard Lovecraft and the Frozen Kingdom; Orion on Justice League; Slade on Teen Titans; etc.
Pierce, David Hyde See actors P
Katana in an ep of Batman: The Brave and the Bold (also voiced by Kim Mai Guest); Julie and Ship in Ben 10: Alien Force & Ultimate Alien.
Emperor Zombie in The Amazing Screw-On Head; Cecil Terwilliger in at least one ep of The Simpsons; Dr. Doppler in Treasure Planet; etc.
Posehn, Brian See comedians
Cousin Larry on Kim Possible; Jim on Mission Hill; Octus on Sym-Bionic Titan; Gibbons on Tom Goes To the Mayor; etc.
Prince, Derek Stephen
Sado (Chad) on Bleach (eps 86-?); Jelly Jiggler on Bobobo-bo Bo-bobo; Diethard on Code Geass; Lordgenome on Gurren Lagann; Duke Red in Metropolis; Professor Hiragi on Mon Colle Knights; Giovanni on Pokemon Origins; Martin Zigmarl on s-CRY-ed; Takuma Zaizen on Witch Hunter Robin; etc.
Uryu on Bleach; 009 on Cyborg 009; Dr. Root on Duel Masters; Phantom on MÄR; Mondo on Mon Colle Knights; Dr. Gillen on Monster; Shino on Naruto (and Naruto Shippuden); Sanosuke on Rurouni Kenshin; etc.
Reilly, John C. See actors Q-R
5 in 9; Officer Barry on Stone Quackers; the title character in Wreck-It Ralph; etc.
Richardson, Kevin Michael
Amy Yeager et al. on Case Closed; Fiore on Chrono Crusade; Lyra on Fullmetal Alchemist; Angelica on Gunslinger Girl; Kuina, Tashigi, et al. on One Piece (FUNi dub); Ai on Shin-chan; Yumi Jinnouichi in Summer Wars; Tetsuko on The Super Milk-chan Show; Muu-chan on Tactics; etc.
The Lion Turtle et al. on Avatar: The Last Airbender; the Joker on The Batman; B'wana Beast et al. on Batman: The Brave and the Bold; Lucius Fox in Batman: Gotham Knight; Carlton Duquesne in Batman: Mystery of the Batwoman; Highbreed Commander et al. on Ben 10: Alien Force; Martin Luther King, Jr. et al. on The Boondocks; Junior, Lester, et al. on The Cleveland Show; Skulker et al. on Danny Phantom; Uncle Oswidge on Dave the Barbarian; Trigon on DC Super Hero Girls; Roboto, Nasty Canasta, et al. on Duck Dodgers; Belloc in Firebreather; Roadblock et al. on G.I. Joe: Renegades; Santa Claus and the Easter Bunny in How Murray Saved Christmas; General Wells on Justice League; Captain Gantu in Lilo & Stitch; Ray-Ray and Cheeks in The Little Mermaid: Ariel's Beginning; Slam Tasmanian and Tech E. Coyote on Loonatics Unleashed; Mayor Tilton on The Mask; Glorft Commander et al. on Megas XLR; Beady Brothers in Niko and the Sword of Light; Korg in Planet Hulk; the Boogieman in an episode of Powerpuff Girls; Demongo et al. on Samurai Jack; Tombstone on The Spectacular Spider-Man; Jabba the Hutt et al. on Star Wars: The Clone Wars; Robert Hawkins on Static Shock; Nick Fury on The Super Hero Squad Show; Antauri on Super Robot Monkey Team Hyperforce Go!; Trigon, Mammoth, et al. on Teen Titans; General Aguila in TMNT; Omega Supreme on Transformers Animated; narrator of Trolls Holiday; Bishop on Wolverine and the X-Men; Panda Bubba on Xiaolin Showdown; Martian Manhunter et al. on Young Justice; etc.
Kukaku, Jinta, Kiyone, et al. on Bleach; Zola on Blue Dragon; V.V. and Inoue on Code Geass; Balsa on Moribito; Kosagi and Ryouko on Noein; Dr. Chiba in Paprika; Sakuno on The Prince of Tennis; Cattleya on Rave Master; etc.
Rodriguez, Michelle See actresses Q-R
Liz Ricarro on IGPX.
Romano, Christy Carlson See actresses Q-R
Yuffie in Final Fantasy VII: Advent Children; the title character on Kim Possible.
Root, Stephen See actors Q-R
Penguin, Killer Croc, et al. on Batman: The Brave and the Bold; Mildew on DreamWorks Dragons; Bubbles in Finding Nemo; Bill and Mr. Strickland on King of the Hill; Merrimack and Doc in Rango; Chode on Tripping the Rift; etc.
Rosenbaum, Michael See actors Q-R
Deadman on Batman: The Brave and the Bold; Drago on Jackie Chan Adventures; the Flash et al. on Justice League and in Justice League: Doom; Kid Flash on Teen Titans; Agent West on The Zeta Project; etc.
Rudolph, Maya See actresses Q-R
Mrs. Malocchio in The Awesomes; Aunt Cass in Big Hero 6; Betty in Bless the Harts; Rapunzel in Shrek the Third.
Rukia on Bleach; Kluke on Blue Dragon; Euphemia on Code Geass; Yoko on Gurren Lagann; Fujiko on Lupin the 3rd; Snow, Koyuki, and Loco on MÄR; Hope Stelar on MegaMan Star Force; Yuki on The Melancholy of Haruhi Suzumiya; Tsukiko on Paranoia Agent; Kizna on Pilot Candidate; Elie on Rave Master; Naomi et al. on Zatch Bell!; etc.
Prof. Rotwood on American Dragon: Jake Long; Cosmo et al. on Buzz Lightyear; the Dark Lord Chuckles the Silly Piggy, et al. on Dave the Barbarian; title character on Earth to Ned; title character, et al. on Freakazoid!.