Intoxigator is the first boss of Episode 1 The Foothills. As the name implies, he is a huge intoxicated crocodile, who appears to be contaminating the sewer with his presence. He is very slow, and attacks with acid spit, which can be easily strafed to the side, or blocked by some of the columns or other stuff found in the arena. He possesses 5000HP, which isn't much, but at the time, player's strongest weapon in his arsenal is a Assault rifle (excluding secrets pick ups), which makes the fight last much longer, than it would be later in the game. After killed, you can hear angry mysterious voice screaming "My pet!!".
He is encountered at the end of E1M3. He also has a son, encountered much later in the game.