Boss Guide REO
Here is a list of all Resident Evil: Outbreak Bosses and the description for each one.
The G-Mutant is found at the end of the "Below Freezing Point" scenario. Born from Monica's body, her zombified self dies again after the Embryo bursts out from her stomach. The little thing mutates pretty quickly after arriving at your location. It's actually a lot more easier than it looks, so steer clear away from it and fire away.
 Giant Leech
The Virus has a bad tendency of enlarging parasitic creatures, such is the case with the Leech. As you would expect from a bloodsucking, slimy creature, it also can spit poison which can prove to be very annoying. You find it at the end of "The Hive" scenario, where it blocks your escape route down the sewers.
 Regis Licker
This Licker is by far the most messed up in the RE universe. Her (Regis is a female...or was) guts are spilling out, her legs are mutilated beyond repair, and godamn she can move her tongue better than all the other Lickers. The good thing is that she's a stationary boss, and that's a very good thing, considering the length of her tongue is something look at. Regis is at the end of the "Hellfire" blocking your path to the exit.
Behold, Dr. Greg's creation, pretty much an original looking Tyrant, but its moves are not that much different from other Tyrants. You'll find this giant humanoid in "Decisions, Decisions" midway around the scenario stalking you around the University. He'll first appear after you've collected the first 2 ingredients for the Daylight vaccine.
This is the transformation Thanatos goes through after its taken too much damage like getting caved in a exploding building. For some reason Tyrants get a lot stronger the more damage they take, and Thanatos is no exception. He has an enlarged arm to make up for the one he lost in the explosion, he's limping now but he's really pissed off and does a lot more damage with just that arm. You will be facing him twice, so get lots of ammunition and good weapons, cause he's a whole lot tougher than he was in the University.