L is Real 2401 is a theory / Easter egg in Super Mario 64. It involves the character Luigi and his absence from the game. Legends say that the fountain in the courtyard of Princess Peach's castle is the key in one of gamings most discussed mysteries. As it turns out, Luigi was always there, trapped in the fountain, but something is preventing his escape, holding him deep beneath the fountain. The Tentacles are presumably an unseen part of a much larger creature holding luigi under the fountain