Ouroboros

The Ouroboros is an ancient pagan, alchemical, and gnostic symbol that has appeared in a wide range of texts since antiquity. Its origins are said to be ancient Egypt, but it has also appeared millennia later in Hindu mythology and European folk ritual.

It usually depicts a snake or dragon eating its own tail, thus serving as an apt metaphor for many cyclical (looping) human experiences like self-reinvention, karma, and Eternal Return.

https://www.bbc.com/culture/article/20171204-the-ancient-symbol-that-spanned-millennia