Day 1: A swamp dwelling monster.

A swamp dragon whom breathes putrid-smelling poison, a fierce hunter of the swamps and bogs. Probably just as much of a scavenger/carrion beast as it would be a hunter. Sentient to some degree. Has a fondness for gold and jewels. Very evasive to humans and most other beings (except prey, obviously), fatal to the inexperienced. It's an opportunistic killer.