A Pandronian colony creature and honorary commander who travels on the USS Enterprise as an independent observer, and whose reckless testing of Kirk and Spock endangers a mission to Delta Theta III.
Ari bn Bem appears in the animated episode Bem, written by David Gerrold, and is voiced by James Doohan. He comes from the planet Pandro and is able to separate his body into independently moving parts, each with a mind of its own.
Having stayed aboard for several missions without leaving the ship, he insists on joining the landing party sent to plant monitoring devices among a primitive people. He secretly swaps the officers' phasers and communicators for fakes, wanders off and is captured by the natives.
Kirk and Spock are caged trying to recover him, and all three come under the eye of a powerful intelligence that guards the inhabitants. Ashamed of his errors, Bem proposes to disassemble himself for good, but the entity persuades him that learning from a mistake is better than punishment.