There are a few of these in the game already, and they make a very nice way of diversifying the metagame.
The ability to give interesting abilities to a large variety of creatures in the game is great, and these ideas have largely been successful.
I think it would be cool to create one for each element.
Current ones are:
Liquid Shadow
Butterfly Effect
Acceleration
Mitosis
and, in a way,
Luciferin (Without the skill removal).
What kinds of other abilities do you think would be cool to give to creatures?