Utromidium is a substance that can nullify the powers of the Super Turtles and Sliver).
Utromidium was used by Sliver to trap the Super Turtles in the episode "Reality Check". Sliver dropped the Utromidium, shaped like a giant cage, over the Super Turtles and Michelangelo. Later, Sliver used the controller on his walking stick to create a Utromidium bubble around Blobboid (pretending to be Mikey) and float him out of the cage, showing that the substance is pliable.
