In the Red and Blue versions, it can be found by using a cheating device, and only by this method, since it cannot be caught using the Mew glitch. If this Pokémon is traded to the Yellow version, it will become a ゥ(I'.
$ has no specific habitat because it was never programmed to be in a specific area, nor was it ever programmed for the player to find it. Since it only exists in Generation I, it technically exists in the Kanto region. It has no habitat relating to the Mew glitch. Theoretically, it could also exist in some Glitch City-like location.