Rift of Atrocity

The Rift of Atrocity is one of the most horrifying places to exist in the Eighth Realm. In the seas between the Old and New Worlds, there lies a great trench in the sea, a trench that seems to go down infinitely far (though of course this is not possible). Somehow, the Rift of Atrocity has the ability to spawn monstrosities which rise to the surface to wreak havoc on the world's seas. There are many theories on exactly what the trench is, but nobody truly knows how or why it exists. Most certainly, though, the rift is shrouded in mystery, for few attempt to speak to the Karpori who live near it, and fewer survive making contact. However, a far as it is known, the rift has not even been explored by the Karpori, and it is rumored that the lower one goes, the more frequent and more powerful the monsters get. If this is true, then that makes the monsters spawning from it even more terrifying, for it would mean that they are fleeing from what is in the rift. If this is the case, then whatever lurks at the bottom must be truly indescribably powerful and evil.
Nobody is quite sure whether the rift spawns the monsters via magic, whether they breed down there, or whether they are remnants from the past that simply make their way up to the surface occasionally. Either way, the rift most certainly spawns primarily a few types of monster, with some being more common than others.

Giant Floating Heads with Tentacles? (For some reason these always head west)

Krakens

more ???

Some theorize sea serpents come from the rift (this is canonically wrong but a popular myth)