Soul Mates (Tombstone Twins) - Denise Downer

Dedbert is a student at Underworld Elementary, a school for kids who have died in outrageously wacky ways. Unfortunately, Dedbert doesn't fit into any of the school's necro niches. He died flushing himself down the toilet, and now he's the butt of all butt jokes. Then one day, a new student, Skully, arrives. And guess what? She's Dedbert's death twin they died in the exact same way! These two quickly become friends, and discover that they truly are Tombstone Twins. Soul mates.