Cybertronian jellyfish

Inhabiting Cybertron's lower levels, Cybertronian jellyfish are a life form rarely seen. Dwarfing Transformers, they move with an undulating motion, swimming through the atmosphere as though it was water. Although normally peaceful, they will panic if disturbed. They had a tendency to explode when shot, releasing an electromagnetic pulse that will scramble the circuits of their attacker. They may be immune to Dark Energon.

Transformers: War for Cybertron
As they flew through the tunnels deep within Cybertron in search of the Geosynchronous Energon Bridge, Starscream, Thundercracker and Skywarp encountered some Cybertronian jellyfish. Thundercracker was fascinated, not having seen the creatures before, but Starscream merely saw them as another obstacle.

As Optimus Prime, Ironhide and Warpath neared the entrance to the core of Cybertron, they passed through an area in which a school of jellyfish were swimming.

A number of Cybertronian jellyfish were living in Trypticon's coolant tanks when Jetfire, Silverbolt and Air Raid used a coolant pod to venture down through the liquid.