Tailgate was Arcee's partner back on Cybertron. When Arcee was captured by Airachnid, Arcee was tortured by Airachnid's finger. Airachnid went and told Arcee that she'll never talk and then brought Tailgate out. Airachnid went and put one of her "spider legs" into his chest. Arcee screamed out his name, but all that is seen is Tailgate's energon on the wall.
The Cyberverse toy is a simple redeco of Cyberverse Cliffjumper. Coincidentally, Cliffjumper eventually became Arcee's partner.
- He seems to have the same body type as Cliffjumper.