Blork's Evil Twin — Bruce Coville

DOUBLE TROUBLE ON THE PLANET SPLAT!
Blork has reformed. No longer is he the biggest brat on Splat. But some people, such as Appus Meko, don't like that. Some people thought life was more fun when they could make Blork explode whenever they felt a little bored. Some people are actually trying to get Blork to have another tantrum.

And when Blork gets blamed for the terrible thing that happens to Moomie Peevik at the Museum of New Inventions, it looks like they may succeed.

But that's before the arrival of Blork's evil twin, Krolb -- who just may be the rottenest kid in the history of the planet!