Black tar is a hazard in J-J-Jump, first seen in level 5.
Depending on the level and area the teeny hero is in, black tar fills the entire gap between two hills. It is predominantly black, with a few light blue pixels that flash and bubble at its surface.
Black tar acts similar to black flames, due to the fact that both will instantly kill the teeny hero on contact. Unlike the black flames, though, it is only seen on the ground and never covering the ceiling.
Upon touching it, the teeny hero will explode into pink goo and will be sent back to the last checkpoint touched, or the start, if no checkpoint has been touched. Black tar makes frequent appearances in later levels, sometimes requiring the player to jump several times over large gaps which are covered with black tar.