Mr. Unimportant (AKA Mr. Unauthorized, he goes by both, reluctantly) is unimportant. He is so unimportant that the only person that cares about him is Nobody. He is constantly frowning because of how much he has to put up with, mainly from Mr. Important, who likes to pick on him the most.
Mr. Unimportant lives on the 26th floor of Joe Evil Zincorporated, directly below Mr. Important.