Aboleth

"Could it be that Aboleths are older than the gods...that before the divine ones came to be, such horrors shaped the multiverse? Now there's a chilling thought..."
-Vaqir Zekh'r
  Aboleths are large, amphibious, worm-like creatures that dwell in watery environments such as ocean abysses, deep lakes, and the Elemental Plane of Water. According to legend, they lurked in the primordial oceans before the coming of the gods. They were able to use their minds to reach out and seize control of the burgeoning life forms of the mortal realm, but this control was smashed when the true gods appeared.    Aboleths are said to have flawless memories, passing their knowledge and experience from generation to generation. Their minds are treasure troves of ancient lore, recalling moments from prehistory with perfect clarity. In addition, when they consume a creature, they can add the knowledge and experience of their prey to their own eternal memories.