This is a Wurmple found in the garden of the expert Bayologist in the Hoenn region. The guy was shocked to see a Wurmple five times bigger than a normal one devouring all the Razz Berries in his garden. Apparently, this is why its back is blue. It doesn't move much, only to eat; it doesn't seem interested in evolving, it looks like it's way too lazy for that.
by Eatos_w