Suggestions by @aaronpirelatinedo

James (Smiling Friends)

as Characters Already In The Cartoonverse in What Should Come From The Cartoonverse

Phil Lord and Christopher Miller

as Director in SMG4: War of the Fat Italians

MediExcalibur2012

as We need to find them, before he shows up in SMG4: War of the Fat Italians

Robyn Barry-Cotter

as We need to find them, before he shows up in SMG4: War of the Fat Italians

Spoiler

as We need to find them, before he shows up in SMG4: War of the Fat Italians

Sean Chiplock

as Master... You have come back... in SMG4: War of the Fat Italians

Ike Amadi

as Master... You have come back... in SMG4: War of the Fat Italians

Spoiler

as Master... You have come back... in SMG4: War of the Fat Italians

Zazie Beetz

as If you two want revenge, come with me in SMG4: War of the Fat Italians

James Bailey

as If you two want revenge, come with me in SMG4: War of the Fat Italians

Tom Kenny

as If you two want revenge, come with me in SMG4: War of the Fat Italians

Spoiler

as If you two want revenge, come with me in SMG4: War of the Fat Italians

Elsie Lovelock

as Karen the Cat in SMG4: War of the Fat Italians

Sam Lavagnino

as Frankie in SMG4: War of the Fat Italians

Christopher Sean

as The Special Guest! in SMG4: War of the Fat Italians

Karen Fukuhara

as The Special Guest! in SMG4: War of the Fat Italians

Robyn Barry-Cotter

as The Special Guest! in SMG4: War of the Fat Italians

Emma Myers

as The Special Guest! in SMG4: War of the Fat Italians

Spoiler

as The Special Guest! in SMG4: War of the Fat Italians

Bill Hader

as Wario in SMG4: War of the Fat Italians