Nemesis (G1)

 The Nemesis was a legendary Decepticon warship that factored heavilly into most Generation 1 continuities.

Generation 1 Animated Series
The Nemesis was the ship used by the Decepticons to pursue the Autobots. It crashed into the ocean since there was no one left to pilot it.

Beast Wars
The Nemesis was a legendary warship, the most powerful ever built. According to myth, it was responsible for shooting down the Ark. It was revealed in the series finale that Tarantulas had discovered the wreckage of the Nemesis, and had been refurbishing it for unknown purposes. Following Tarantulas' death, Megatron discovered the rebuilt ship and commandeered it as a last ditch attempt to rewrite history and destroy The Ark.

Using the Nemesis's awesome power, Megatron managed to kill Tigerhawk as well as Inferno and Quickstrike by accident.