Soundwave

Megatron's right-hand man. A loyal and cold subordinate, he is often tasked with spying on the Autobots, which he often accomplishes with the aid of his cassette minions Laserbeak, Frenzy, Rumble, Buzzsaw and Ratbat.

In the Headmasters anime, an aide to Galvatron.

His altmode is a cassette player.