An idea I've been entertaining for some time is a Ground/Ghost pokemon based on, obviously, zombies. Of course since Pokemon is more of a kids game, it wouldn't have bloody intestines or anything showing; I was more-so thinking a blob-like creature with the appearance of a humanoid upper body (torso, two arms and head) that comes out of the ground, crawling around with a skull for a head - similar looking to Duskull and Dusclops - and a tongue sticking out from underneath. It would have very high HP, Attack and Defense stats, but everything else would be pathetic (zombies are slow, can only attack at melee, and are weak to energy-based attacks like fire). Anyone else like it?
Playing) Fire Emblem: Awakening, Guild Wars 2 Waiting) Pokemon XY
A friend of mine created a Zombie pokemon once. It was Ground/Dark, because we both agreed that zombies don't fit into the ghost category AND they are usually burrowed in the ground. Ground/Poison is another typing that'd make sense, if only because zombies generally are highly infective.