In Greek mythology[1] and religion,

In Greek mythology[1] and religion, the thiasus (Greek thiasos), was the ecstatic retinue of Dionysus, often pictured as inebriated revelers. Many of the myths of Dionysus are connected with his arrival in the form of a procession. The grandest such version was his triumphant return from "India", which influenced symbolic conceptions of the Roman triumph and was narrated in rapturous detail in Nonnus' Dionysiaca. In this procession, Dionysus rides a chariot, often drawn by big cats such as tigers, leopards, or lions.

The thiasos of the sea god Poseidon is depicted as a triumphal wedding procession with Amphitrite, attended by figures such as sea nymphs and hippocamps.

In historical Greek society, thiasoi (plural) were religious organizations whose existence was protected by law.[2]