It's the SML2 Octopus boss, who bears more than a slight resemblance to the Parodius hero Takosuke in this recolor! I colored him from memory (in his Super Mario Adventures palette), so don't be mad if he's not true to the official art.
My entry to sprite competition #90. A basic Mario tileset in the CGA pallette (16 colours). Includes all the other 4 colour CGA Pallettes also, along with a greyscale "GameBoy" one for the sake of it.