You'll need a boat to get to Jormungand. Odin banished him to the ocean at the beginning of time, and he hasn't moved much since. He's kind of hard to miss, though. First, he's a serpent. Second, he's long enough to wrap around all of Middle-Earth and bite his own tail. So yeah, you can't really miss him. But if you find him sleeping, don't wake him. Not only will he probably sink his poisonous fangs into you, but his movement will churn the waves, setting Ragnarok (the end of the world) in motion.
Build: Long, large, and slithery
Hair Color: You mean scale color?
Facial Hair: If he has a beard, it looks like this.
Scars/marks/tattoos: A scar from a puncture wound from Thor's fishing hook
Jewelry and accessories: Coils
Clothing: Just the birthday suit
Type of Weapon: Venomous fangs
He swims with the fishes. And whales, before he eats them.
Under the sea
On or under a sunny rock
The reptile house