Derpy as Ren (Both are angry)

Spike as Stimpy(They're both s)

Dinky as Stinky(Their names rhyme and Stinky is Stimpy's son and Dinky is Derpy's daughter)

Big Macintosh as Mr. Horse

Rainbow Dash as Powdered Toast Man(They're both heroes)

Lightning Dust as Waffle Woman(They're both enemies to the heroes)

Pinkie Pie as Sven

Twilight Sparkle as Ren's Mom

Shining Armor as Ren's Dad