25th century

Chameloids are a species of shapeshifters that some believe to be mythical.

Starfleet officers James T. Kirk and Leonard McCoy met a chameloid named Martia during their imprisonment on the penal colony Rura Penthe in 2293. (Star Trek VI: The Undiscovered Country)

A non-canon source, Peter David's novel Imzadi, has a chameloid character serving aboard a future version of the starship USS Enterprise. The character is described as tall and fur-covered possibly resembling the "brute" form taken by Martia in The Undiscovered Country.