Well, it's actually hard to get if you did not see Season 2 and 3 of Beast Wars, but here's a short filler so you'll hopefully get this Mosaic:
Rampage (a.k.a. Protoform X) - failed experiment of Cybertronians who tried to clone the Immortal Spark of Starscream, but failed. transforms into a Transmetal crab. very violent and suffers constantly from having his indestructible Spark (which was taken from his body FYI) being tortured upon constantly by Megatron (who encases it in a small chamber with Energon spikes, and squeezes it ala stress balls whenever Rampage doesn't follow his command).
Depth Charge - the main character in this Mosaic. sworn enemy of Rampage, who destroyed his security station/planet. transforms into a transmetal manta ray.
events leading to this mosaic:
in their final appearance during season 3, we find Depth Charge and Rampage battling underwater near large deposits of Energon crystals (which are high explosive due to their unstable nature).
they battle with Energon crystal shards, and Depth Chrage manages to pin down Rampage. despite the fact that killing Rampage will detonate the Energon deposits around them, Depth Charge still stabs the Energon shard into Rampage's spark, detonating the Energon around them and killing them both.
basically, this mosaic is a "What If?" type of comic, playing around the facts that Rampage's spark is nearly indestructible (though only Energon can seem to damage it) and that Depth Charge was reissued under the Universe Line, with colors similar to the ones used in this mosaic.
hope this helps.
