One of the Undertale inspired t-shirts. In my shop you can find other characters like Sans, Papyrus, Muffet, Flowey, Undyne, Asriel, Mettaton, Asgore and Gaster.
NEW BETTER DEMON CAT DESIGN HERE: https://www.teepublic.com/t-shirt/2617930-approximate-knowledge?store_id=107395
"I have approximate knowledge of many things." - Demon Cat from Adventure Time