MEGATRON

Function: Decepticon Leader
Allegiance: Decepticon

"Conquest of the universe rests upon the
immediate termination of all Autobots!"

Another pic of Megatron

First cartoon Appearance: 
none -as an Action Master
First Comic Appearance: none

Other Appearances: My goodness Megatron
has had many incarnations:

1984: The original Megatron
1990: this Action Master version
1993: Generation 2, giant green tank
1994: G2, air rocket launcher, purple tank
1995: G2 silly "gobots" version
Oh, and all those Beast Wars/Machines versions,
which was explained, were different individuals.
1997: Machine Wars Version
2001: Robots in Disguise: Megatron