Steam Lord
From Prime3
Discovered by petrie911
Fight in 1:04 http://www.youtube.com/watch?v=O8G82jaAEMU
"Turns out that hyper mode actually isn't the way to go for Steamlord. You start out by hyper beaming the bots (they go down in 4 hits each), then drop out of it and start charging and missling the steamlord. When he's not onscreen, keep destroying steambots so that there's always at least one destroyed steambot at all times." (from M2K2 forums)