Ouroboros
From Halopedia, the Halo wiki
Ouroboros
Ouroboros is an achievement in Halo: The Master Chief Collection. It is unlocked by beating the 25 minute par time on the level Infinity. The achievement is worth 10 Gamerscore and can be unlocked on any difficulty.
Trivia[edit]
The ouroboros is an ancient symbol depicting a serpent or dragon eating its own tail. It represents cyclicality, or infinity.