Quake on the Brain
 
 
 
  The creature is the Owlbear like Mutant from Quake 2, and the gun is my interpretation of Doom's plasma gun in Quake 2.
 
 
 
  Some sort of variation on the Grenade Launcher theme.
 
 
 
  Combo Gunner/Berserker (both from Quake 2). Has the Gunner's grenade launcher, and the Berserker's spikey-drilly thing...