So... Swapfell is just one of people who hang around somewhere and screw crap up. Yes, he is 'insane'.

If you're wondering about the cracks on his arms, let's just say Swapfell messed with Fell's mate.

He personally LOVES to mess with Emily since he knows she likes Stars. That, and she takes way to many things seriously.

Swapfell is sometimes forced to work with Swap or Emily and B. Fell doesn't trust him near Zoey, WingDing, and Stars for A LOT of reasons.