What is the black item in Tigris' chest?

[Sir Prime A Lot]

I opened up his chest and there's something in there which looks like a Matrix. What is it?

Also I realized you can actually pull the spikes off his shoulders, they're removable. Just in case anyone didn't know.

[Sun Swipe Prime]

It's a bomb from the comic book I believe.

[Transbot90210]

It's chromed if you bought from PSX :P But ya, it is a bomb from the comic. Just a cool neat little extra.