Rivett is a Vermillion. Many vermillion look identical to him.
Rivett was hatched from eggs of The Great Devourer, like all the other Vermillion.
Rivett attacked Mega Monster Amusement Park and was destroyed there, but reformed like all Vermillion do.
Rivett traveled back in time aboard Iron Doom. They engaged in battle to defeat the Elemental Alliance. The Time Twins used the control helmets to instantly destroy all their Vermillion, including Rivett. They were then fused with the Iron Doom, and were lost in time with it.
- Rivet's minifigure sports the same armor style as Commander Raggmunk over his torso, which has the same printing as Tannin's.