Catoblepas
Large Magical Beast
Hit Dice: 6d10+18 (51 hp’s)
Initiative: -1 (Dex)
Speed: 20ft
Armor Class: 11 (-1 Size, +3 natural, -1 Dex)
Attacks: Tail Slap +8 (Criticals on a 19 or 20)
Damage: Tail Slap 1d4 + stun
Face/Reach: 5ft x 10ft/ 10ft
Special Attacks: Death Gaze
Special Qualities: Low-light and Dark Vision (60ft)
Saves: Fort +8, Ref +4, Will +1
Abilities: Str 8, Dex 8, Con 16, Int 3, Wis 8, Chr 6
Skills: Hide +3, Listen +6, Spot +7
Feats: Alertness, Improved Critical
Climate/Terrain: Any swamp
Organization: Solitary or in a pair
Challenge Rating: 4
Treasure: None, standard in lair
Alignment: Always Neutral
Advancement Range: 6-9 HD (Large)

See the 2nd Edition AD&D Monstrous Manual for more information.

Combat:
Catoblepas will attack anything that enters it territory or if it feels threatened.  Normally though, it will simply size up adventurers, leaving them be if they look too strong.  A mated pair will attempt to herd foes into a death gaze crossfire.  
	When they hit with their tails, they have a 75% chance of stunning their prey.  This chance is dropped by 5% for every level (or Hit Die) past the first of the target.  If a target is stunned, it stands there for 1d10 rounds.  

Death Gaze: Range of 60 yards, pass a Will save or die (DC 12).  If a catoblepas leaves anyone in a party flat-footed, they have a 1 in 6 chance of meeting the gaze of the creature, otherwise there is only a 25% chance that the catoblepas will raise it’s head to use the gaze attack.  However, if the creature and its prey are standing relatively still, this chance increases to 15%, but if the creature must follow quick movements it has only a 10% of using its gaze attack.

Society:
See the 2nd Edition AD&D Monstrous Manual for more information.