An ettin, H, is a huge humanoid carnivore. They are hard to surprise; they ignore stealth 9 turns out of 10. This is presumably because they have two heads. Despite this, decapitation with Vorpal Blade is still an instant kill.
Generally, the player will encounter ettin zombies before actual ettins.
It is common for ettins to have two heads in other games related to Dungeons & Dragons.
The two-headed giant, or ettin, is a vicious and unpredictable
hunter that stalks by night and eats any meat it can catch.