Suggestions by @vikingwendigo

Dave (Given Name)

as Childish Dad in Space Spam

Dean Wendt

as Barney the Dinosaur in Space Spam

Maverick Trevillian

as 67 Kid in Space Spam

Jeff Bennett

as Ace D. Copular in Space Spam

Dameon Clarke

as Cell in Space Spam

Rob Schneider

as Norm in Space Spam

Charles Martinet

as SMG4 Mario in Space Spam

Lance Thirtyacre

as Jeffy in Space Spam

Erin Fitzgerald

as Parasoul in Space Spam

IShowSpeed

as IShowSpeed in Space Spam

Michael Douglas

as Guy-Am-I in Space Spam

Christopher Sabat

as Vegeta in Space Spam

Bill Fagerbakke

as Patrick Star in Space Spam

Keanu Reeves

as Shadow the Hedgehog in Space Spam

Kevin Afghani

as Waluigi and Wario in Space Spam

Chris Netherton

as Does Bad Things Guy in Space Spam

Shaquille O'Neal

as Shaquille O' Neal in Space Spam

Mephiles the Dark

as The antagonists in Space Spam

Does Bad Things Guy

as The antagonists in Space Spam

Tiff Crust

as The antagonists in Space Spam