Cremator

Combine Cremator is a cut Combine transhuman, originally intended to fight player and dispose of Resistance members' bodies during the Combine War.

Concepts
Originally, a Cremator would appear as transhuman, very much like Stalker or Overwatch Soldier. During Combine War, its job was to fight rebellion and dispose of dead bodies through use of Immolator - large, flamer-like cannon, spraying arrays of acid fuel, which would momentally disintegrate any organic matter. However, they were intended to use this weapon against player, too, much like Stalkers use their welding lasers. Also, it would be possible for player to obtain one Immolator, which could be very effective against different parasitics, such as headcrabs and zombies

Half-Life 2
Eventually, (possibly due to deadline), Cremator was cut completely from final version of a game, along with his weapon. However, an Easter Egg was left in game as Cremator's head, conserved in formaline on Eli's table in Black Mesa East. Also, it is possible that Cremators exist in Half-Life universe, as there are lots of burnt-down bodies in the game, located mostly in places, where Overwatch executed their clean-ups. Such places are, for example, canals and houses near Highway 17.