BULL SQUID
The Bull Squid is that annoying alien that spits acid, ate headcrabs, and could kill you at close range with one hit. He hasn't changed much, but you can tell the difference.

bullsquid.jpg (60780 bytes) This old Bull Squid is in the water, just like he does now

bullsquid0.jpg (7289 bytes) Just a Bull Squid

bullsquid1.jpg (91648 bytes) This old Bull Squid is about to attack an old scientist

bullsquid2.jpg (71389 bytes) I'm not sure why, but the Bull Squid used to be yellow. Some people think that this is was a completely different alien and that his name was Bull Chicken because it was shy.

bullsquid3.jpg (46386 bytes) This is proof that this is probably a Bull Squid rather than a Bull Chicken because in this same spot in the real game is a Bull Squid