Suggestions by @sioxk

John Lithgow

as Dr. Curt Connors in Spider-Man & Supergirl

Kevin Michael Richardson

as Perry White in Spider-Man & Supergirl

Naomi Scott

as Karolina Dean in Spider-Man & Supergirl

Rose McIver

as Elektra in Spider-Man & Supergirl

Kate Mara

as Lois Lane in Spider-Man & Supergirl

Greg Cipes

as Danny Rand in Spider-Man & Supergirl

Seth MacFarlane

as M.O.D.O.K in Spider-Man & Supergirl

Michael Rooker

as Yondu in Spider-Man & Supergirl

Michael Douglas

as Hank Pym in Spider-Man & Supergirl

Patton Oswalt

as Scott Lang in Spider-Man & Supergirl

Eric D. Ward

as Darkseid in Spider-Man & Supergirl

Patrick Stewart

as Xavier Charles in Spider-Man & Supergirl

Laurence Fishburne

as Norrin Radd in Spider-Man & Supergirl

Jennifer Tilly

as Black Cat in Spider-Man

Rachel MacFarlane

as Jessica Cruz in Spider-Man & Supergirl

Ron Perlman

as Slade Wilson in Spider-Man & Supergirl

Cree Summer

as Nebula in Spider-Man & Supergirl

David Sobolov

as Drax in Spider-Man & Supergirl

Jennifer Carpenter

as Gamora in Spider-Man & Supergirl

Seth MacFarlane

as Rocket Racoon in Spider-Man & Supergirl