Origin - Animated
Lockdown was originally a student in Yoketron's Cyber-Ninja Corps. Lockdown was Yoketron greatest until during the Great War he brought on shame to the corps and was kicked out of the corps. It is unknown what he did to cause his exile from the Cyber-Ninja Corps, however Lockdown eventually joined the Decepticons and became a Bounty Hunter. His first job was to was to lead a Decepticon attack on Yoketron's training center and to steal the protoforms kept in storage. During the attack, he killed Yoketron and took his helmet as a Trophy.
Transformers Movie continuity
Lockdown also appeared in the Transformers Animated series and in the online series, Transformers: Cyber Missions, which was based around the film, Revenge of the Fallen. The IDW comic character design is based on the Lockdown that appeared in Transformers: Cyber Missions.
He is set to appear in Transformers: Age of Extinction