Hippomaritimus

Notes:

 * Spawns every 60~90 minutes.
 * Found at the Siren Sands beach (H/I-9).
 * Seems to be non-aggressive. Doesn't seem to aggro by sight and/or sound.
 * Will use Intimidate (Pugil) and Screwdriver.
 * Seems immune to Sleep, Sleep II, Bind, Repose and Gravity
 * Blind, Poison, Bio, Paralyze, and Slow work on it.

Historical Background
"Hippo" refers to the Ancient Greek word for "horse", and "maritimus" can mean "of the sea" or "of the coast". Therefore, this monster's name means either "horse of the sea" or "horse of the coast", by interpretation.