Galvatron clone
In July of 2012 Megatron disappeared for several months, during which Starscream took over the Decepticons. Nemesis began construction of a Galvatron clone to control in case he needed to take over the Decepticons from Starscream. However, Megatron's return in 2013 made this contingency plan unnecessary. Nonetheless, Nemesis has the almost-completely clone in reserve in case it is needed for other purposes.
Artillery cannon mode
In 2014, Megatron and Nemesis hatched a plan to use the clone to draw out the remains of the Cult of Galvatron, as well as test the loyalty of Megatron's troops. During a staged fight, the clone of Galvatron destroyed a clone of Megatron, claiming new leadership of the Decepticons. However, the Decepticons united under Starscream to oppose "Galvatron", and vowed to bring Megatron back to life. Starscream was successful in his quest, and Megatron was seemingly returned to life.
In 2015, Galvatron and Megatron met in battle in the skies over Polyhex. "Galvatron" was killed, but not before activating a beam that reformed Polyhex into an alien city reminiscent of Unicron.
Galvatron clone