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