Teenage Mutant Ninja Turtles (1987): Season 10, Episode 7

10 - 7: The Day the Earth Disappeared

Lord Dregg has managed to open a gigantic portal that is large enough to pull the entire Earth into Dimension X. While trying to figure out how to stop it, Leonardo, Donatello and Master Splinter are pulled through the portal, after Dregg turns the portal on them.