Guards[]
These three Tilonians served as guards at the Tilonus Institute for Mental Disorders on Tilonus IV in an illusory reality created to receive secret information from Commander William T. Riker. The first guard was also part of the known reality and was knocked down by Riker shortly before he was beamed aboard the USS Enterprise-D. (TNG: "Frame of Mind")
Inmates[]
These Tilonian inmates were held at the Tilonus Institute for Mental Disorders on Tilonus IV in an illusory reality created to receive secret information from Commander Riker. They entertained themselves in the common area of the institute with painting and working with clay and objects. According to another inmate, Jaya, the first was Sanders from the USS Yosemite and the second one was Stafko from the USS Yorktown. (TNG: "Frame of Mind")