Ettin

 Ettins, eh? A great example of how a simple stat block with one neat ability can make for a really, really memorable encounter. The ettin's heads acting on different turns in the initiative is a really neat touch, though, and will make your players rethink their tactical approach as the creature gets to adapt and react to their actions at twice the rate of any other.

Blognaag and Thrognaag are an especially loquacious ettin with a highly specific MO. Standing vigil at the twin doors that lead into the famed Jotunhard dungeons, Blognaag and Thrognaag will greet any potential visitors by explaining to them how one only speaks the truth while the other one always lies, and how one door leads to great treasures while the other leads to certain death. In truth, the whole mystical schtick is a ruse itself - the ettin is a manipulative liar but perfectly capable of telling the truth if need arises, and both doors lead to a deep pit ending in spikes, and the cunning ettin merely enjoys playing others' intelligence on themselves, coming in to finish off the "nerds" and take their treasure after the deadly fall.

Deep in the vaults of the Sorceruos Constructs penitentiary, the most feared artifact is hidden. The murderer's coin is a simple enough object - a small piece of gold, with an alien deity on it's face. However, when no-one is looking at it, the coin has the tendency to teleport itself into random people's pockets, and whoever but touches it with bare skin, dies instantly. So far, the only way to contain it has been to have four ettins, working in tireless shifts to just stand and stare at the coin. However, as the ettins grow restless from the lack of action, a more permanent solution must be found.

Krook and Pnook are two ettin heads in a heavy predicament. When Krook sat on Pnook's favourite chair (an old throne from a raid years past), Pnook decided the offense was grave enough to warrant murdering Krook. Ever since then, he has been sabotaging Krook's every effort and attacking him at every point - whereas poor Krook is seeking help from the same villagers he had raided for years, feeling Pnook manages to find him whereever he tries to run or hide.