The Creepy Mario head first appeared in Mario Teaches Typing 2 for the PC. He is commonly seen in YTPs and MLG parodies.
He looks very similar to the Stretchy Mario Head in Super Mario 64 but a lot more wider and creepy. In a way, he looks like the Hotel Mario version of Mario.
Appearances in Chadtronic Edit
The Mario Head is seen briefly in Chad's Review of Mario Teaches Typing. (The video has since been removed from channel.)