Yuan-ti Anathema
Huge natural magical beast (reptile)
Level 21 Elite Skirmisher XP 6400

Initiative +18        Senses Perception +17
HP 412; Bloodied 206
AC 37; Fortitude 39, Reflex 35, Will 35
Resist 20 poison
Saving Throws +2
Speed 8
Action Points 1

(⚔) Slam (standard, at-will) ✦ Poison

Reach 3; +26 vs AC; 2d6+7 damage, and ongoing 10 poison damage (save ends).

⚔ Double Attack (standard, at-will) ✦ Poison

The yuan-ti anathema makes two slam attacks, each against a different target.

⚔ Bite (standard, at-will) ✦ Poison

Reach 3; +26 vs AC; 2d8+7 damage, and the yuan-ti anathema makes a secondary attack against the same target.

Secondary Attack +24 vs Fortitude; the target takes ongoing 15 poison damage and a -4 penalty to attack rolls (save ends both).

⚔ Trample (standard, at-will)

The yuan-ti anathema can move up to its speed and enter enemies' spaces. This movement provokes opportunity attacks, and the anathema must end its move in an unoccupied space. When it enters an enemy's space, the anathema makes a trample attack; +24 vs Reflex; 2d6+7 damage, and the target is knocked prone.

ᗕ Horde of Snakes (standard, recharges when the yuan-ti anathema uses swarm of snakes) ✦ Poison

Close burst 1; +26 vs Fortitude; 2d4+6 damage, and ongoing 10 poison damage (save ends).

Swarm of Snakes (move; at-will)

The yuan-ti anathema collapses into hundreds of snakes, which shift up to 8 squares away and then reform as the anathema in an unoccupied space. The anathema ignores difficult terrain while moving in this fashion.

Alignment Evil        Languages Draconic
Str 25 (+17)      Dex 23 (+16)      Wis 15 (+12)
Con 30 (+20)      Int 5 (+7)      Cha 22 (+16)

Published in Monster Manual, page(s) 271.