Ah grapple monsters. That's how to beat a Chain Tripper. Well, it helps when they don't have Improved Trip to screw your AoO over. Sure, we can make the Lesser verion. The Fey version actually is weaker if you gave them both HD (or racial weapon profs). Do remind me what the stats are on the Diaboli, just so I know what I'm getting myself into.
Dragon Compendium version:
DiaboliMedium Outsider (chaotic, native) (changed to Fey, keep the chaotic or lose it? I got no firm opinion, but it does seem appropriate for Fey)
Base speed 30
Darkvision 60
+2 racial saves vs spells/spell-like
+2 Intimidate vs humanoids/animals
-2 Diplomancy, Handle Animal, Perform & Sense Motive
Tridents as simple weapons
Tail attack (1d4)
Poison 3+Con/day
sickens for 2d4 rounds
Favored Class: Sorcerer
LA +1
The Dragon 327 version has no daily limit on poison uses and LA+0, but is otherwise identical.