Drek hits (rolled 19) for 9 points of damage! The sludge is at -6 HP and dying. The bad news is that Drek's warhammer got some of Sludgy stuck to it, and Drek could not shake it off fast enough (rolled 3 on reflex save). Drek's warhammer is now drek, so your only weapon is the crossbow at your feet.
A strange, not-quite humanoid creature enters the arena and moves to 30N110E. It has three heads, but only the central one has any features, although the features are strange (three eyes, no mouth). It has three arms, two ending in spikes instead of hands, and the third protrudes from its chest and has three slender fingers. It has three legs, the outer two ending in stumps and the central one has three toes. Below the central arm is a large mouth with three short tentacles above it.
When the bizarre (to say the least) creature reaches 30N110E, there is a blinding flash of light. After Drek's eyes accustom themselves again to the arena, there are now three of the bizarre creatures, one at 35N105E, one at 30N110E, and the third at 25N110E.
Your move, Drek.