Eric Grimm is the least happy resident of Blackbury Cemetery. This is despite the fact that he's the only one who joined voluntarily. Although he seems to be the only interee dissatisfied with his afterlife, he's also the only one who doesn't want to leave and see the world with the rest. He had/has thick glasses, a small mustache and a smaller capacity for joy.
Probably he brought his depressed and depressing personality with him from life and is stuck with it: he committed suicide on May 21, 1927. When the rest of the Dead leave to explore the world(s), Grimm remains. Johnny leaves him a small television set.