Suggestions by @aardwolf

Elle Fanning

as Echo Echo in Ben 10: Omniverse (Live Action)

Amy Poehler

as Buzzshock in Ben 10: Omniverse (Live Action)

Emma Watson

as Big Chill in Ben 10: Omniverse (Live Action)

Mark Hamill

as Ghostfreak in Ben 10: Omniverse (Live Action)

John Goodman

as Cannonbolt in Ben 10

Zendaya

as Jetray(Voice) in Ben 10

Mark Hamill

as Ghostfreak in Ben 10

Mark Hamill

as Ghostfreak in Ben 10 Alien Force

Tom Hardy

as Ripjaws in Ben 10

Keanu Reeves

as Diamondhead in Ben 10

Tom Holland

as Xlr8 in Ben 10: Ultimate Alien (Live action TV show)

Mindy Kaling

as Upchuck in Ben 10

Jonah Hill

as Upchuck in Ben 10

Amy Sedaris

as Upchuck in Ben 10

Seth Rogen

as Upchuck in Ben 10

Joaquin Phoenix

as Four Arms in Ben 10

Sarah Silverman

as XLR8 in Ben 10

Brie Larson

as Heatblast in Ben 10

Jennifer Lawrence

as Heatblast in Ben 10

Zac Efron

as Chromastone in Ben 10