Ankheg

Horse-sized, rust-brown insects. They burrow vast, underground warrens into the bedrock.

AC 14, HP 14, ATK 1 bite +4 (1d6) or 1 acid spray (near) +4 (2d6), MV near (burrow), S 2, D 2, C 1, I -2, W 1, Ch -2, AL N, LV 3