Suggestions by @andymayer

FLCL

as Deadpool in Which projects should inspire adaptations of these comics

Knives Out

as Scooby-Doo in Which projects should inspire adaptations of these comics

Ian McKellen

as "Old George" in Ben 10: Heroes United

Tim Curry

as Dr. Joseph Chadwick in Ben 10: Heroes United

Ralph Ineson

as Forever King/Enoch Driscoll in Ben 10: Heroes United

Keke Palmer

as Rook Shar in Ben 10: Heroes United

Amber Midthunder

as Kai Green in Ben 10: Heroes United

Lana Condor

as Julie Yamamoto in Ben 10: Heroes United

Sarah-Nicole Robles

as Elena Valadus in Ben 10: Heroes United

Clifford Chapin

as Drax in Ben 10: Heroes United

Bobby Moynihan

as Tack in Ben 10: Heroes United

Kyle McCarley

as Scout in Ben 10: Heroes United

Nicolas Cantu

as Cooper Daniels in Ben 10: Heroes United

Kate Micucci

as Lucy Mann in Ben 10: Heroes United

Steven Yeun

as Pierce Wheels in Ben 10: Heroes United

Allegra Clark

as Helen Wheels in Ben 10: Heroes United

Caleb McLaughlin

as Alan Albright in Ben 10: Heroes United

Dee Bradley Baker

as Astrodactyl in Ben 10: Heroes United

Yuri Lowenthal

as Kickin' Hawk in Ben 10: Heroes United

John DiMaggio

as Whampire in Ben 10: Heroes United