This thread is dedicated to posting headcanon voice lists, if any, for your characters and their mons. My list, currently, is below.
Note that this list is incomplete and subject to change, and will be updated as more headcanon voice ideas come to light.
Kimberly Bond: Sierra Boggess- Principal Mullins- School of Rock (musical)
Paul: Jess Harnell- Wakko Warner- Animaniacs
Sinatra: Bradley Cooper- Rocket Racoon- Guardians of the Galaxy films/MCU
Dio: Alex Brightman- Dewey Finn- School of Rock (the musical)
Kaylan: Greg Ayres- Koda Kouji- My Hero Academia
Geddy: Geddy Lee, natch
Elton: Tom Holland (singing voice: Taron Egerton)
Freddie: Toby Jones- Dobby- Harry Potter franchise
Orwell: Rob Paulsen- Pinky- Pinky and the Brain/Animaniacs
Joel: Bill Barretta- Rowlf- The Muppets
Dave: Gary Schwartz- Demoman- Team Fortress 2
Ozzy: Darby Cupit- Frog- Man on the Internet: Chrono Trigger the Musical
Dalt: Baker Terry- Yellow Guy- Don’t Hug Me I’m Scared
Peechee: Mark Hamill
Gallag: Andrew Stanton- Crush- Finding Nemo
Gilmour: Alan Rickman (RIP)- Marvin- The Hitchhiker’s Guide to the Galaxy
Boseman: Chadwick Boseman (RIP)- T’Challa- Black Panther
Jagger: Alex Brightman- Beetlejuice- Beetlejuice (musical)
Strummer: 2D- Gorillaz
Grohl: Zach Callison- Steven Universe- Steven Universe
John: John Oliver
George: Benedict Cumberbatch
Ringo: Ian Tucker- Gavroche- Les Miserables (Original Broadway Cast Recording)
Jinx: Wendie Malick- Eda Clawthorne- The Owl House
Debussy: French- Loic Suberville- TikTok
Leonard Braker: TBD
Walter: Anderson Cooper
Cuddles: Kyra Kupetsky- Chickn Nuggit- Chickn Nuggit
Jules: Micheal J. Woodard- Arlo Beauregard- Arlo the Alligator Boy/I <3 Arlo
Romea: Mippa- Undyne- Undertale: The Musical- Man on the Internet
Serkis: Andy Serkis- Gollum- LOTR franchise
Panto: Nancy Cartwright/Christine Cavanaugh (RIP)- Chuckie Finster- Rugrats
Charon: Tom Kenny- Hal Gibson- Super Robot Monkey Team Hyper Force Go!
Lithium: Aaron Tviet- Danny Zuko- Grease Live!
Scramble: Bill Thompson (RIP)- Droopy
Snoop: Dave Foley- Yes-Man- Fallout: New Vegas
Caboose: Michael J. Caboose- Red vs. Blue
KL-RY: TBD
Buffy: Guy Fieri
Chernobog: TBD
Heracles: Phil LaMarr- Jack- Samurai Jack
Thanatos: TBD
Axis Hunter: TBD
Tekkan: John Moschitta, Jr.
Puxiki: TBD
Letina: Maya- Borderlands 2
Axollo: Steve Blum- Guilmon- Digimon Tamers
Neziey: TBD
Viscor: TBD
Ingrid Anderson: Judy Garland- Dorothy Gale- The Wizard of Oz
Annafrid: Mollie Weaver- Conya- Magical DoReMi
Bjorn: Richard Horvitz- Alpha 5- Mighty Morphin’ Power Rangers
Benny: Andre Braugher- Raymond Holt- Brooklyn Nine-Nine
Agnetha: Andrea Libman- Fluttershy- My Little Pony: Friendship is Magic
Ananpi: Christina Vee- Fwench Fwy- Chickn Nuggit
Bitey: TBD
Bindi: Mae Questal (RIP)- Olive Oyl- Popeye shorts
Amity: Rebecca Soler- Reanne Griffiths- Magical DoReMi
Angia: Tracy Grandstaff- Daria- Daria
Owen Edmundson: TBD
Stipax: Colleen O’Shaugnessy- Tails- Sonic franchise
Nautilu: TBSkyen
Crina: Kat Cressida- Dee Dee- Dexter’s Laboratory
Chasmo: Morgan Freeman
Teryx: Sam Vincent- Edd/Double D- Ed, Edd, n Eddy
Saura: Evanna Lynch- Luna Lovegood- Harry Potter franchise
Steggy: TBD
Eurypedis: TBD
Anomalo: TBD
Cephalo: Matt Hill- Ton-Ton- DinoTrux
Gwana: TBD
Archie: TBD
Tyrie: TBD
Rhamphor: TBD
Laurie Hitoki: TBD
D’Autry: Jack McBrayer- Wander- Wander Over Yonder
Draiman: TBD
MC-DC: Edward Bosco- Alastor- Hazbin Hotel
Hetfield: Anthony Bowling- Grouse- Borderlands 3
Slipknot: TBD
Zoltan: TBD
Plant: TBD
Headcanon Voices
Headcanon voice list for WAAPT characters and their mons if necessary.