Superman writer/director James Gunn is well known for including actors he enjoys working with in multiple projects, and this summer's big DC movie is no exception, as it includes an appearance from several members of the Guardians of the Galaxy, Gunn's big Marvel franchise.
As it turns out, Guardians actors Bradley Cooper (Rocket Raccoon), Pom Klementieff (Mantis), and Michael Rooker (Yondu) as three of Superman's helper robots that populate his Fortress of Solitude.
