Deerclops Eyeball

Master Mode only, so Deerclops has to die on that difficulty for the drop to exist at all. The odds are generous once you are there, and a couple of kills normally settles it.

You get a shrunken Deerclops that walks after you. When you pull too far ahead or leave the ground it does not blink to your position the way most pets do. A bird swoops in, grabs it, and hauls it over to you, which is the whole reason to pick this one over the rest of your collection.

Every part of it points back at Don't Starve. The bird is a Snowbird, and the item and buff tooltips are both taken from character examination lines in that game.