Na'ka'leen Feeders
From Multiversal Omnipedia
The na'ka'leen feeders were alien creatures reminiscent of an octopus in appearance, which feed on neural energy. The na'ka'leen feeders were found on a world the Centauri colonized. The creatures destroyed the entire colony, and the planet was quarantined.
A crimelord on Babylon 5 named Deuce brought a na'ka'leen on-board, and had it pretend to be Ambassador Kosh in a ploy to trick his rivals into thinking he had Vorlon support. The creature was destroyed by a security team led by Garibaldi.