The following is a list of Klingon calisthenics program holograms.
Feathered alien []
This feathered ornithoid alien was a holographic opponent in Worf's Klingon calisthenics program on board the Enterprise-D. It was part of the program when K'Ehleyr ran it and attacked her twice. (TNG: "The Emissary")
Insectoid alien []
This insectoid alien was a holographic opponent in the Klingon calisthenics program, created by Worf aboard the Enterprise-D.
When Commander William T. Riker accompanied Worf for the first time into this program, this opponent attacked Worf but was knocked down by Riker. (TNG: "Where Silence Has Lease")
It was also activated when Worf increased the program to level two in 2365 while he and K'Ehleyr used the program. (TNG: "The Emissary")
Skull monster []
The skull-faced alien was part of Worf's Klingon calisthenics program on board the USS Enterprise-D. (TNG: "The Emissary", "New Ground")
When Commander Riker accompanied Worf for the first time into this program, this skeletal opponent attacked Worf while Riker had to face the insectoid opponent. (TNG: "Where Silence Has Lease")
The same year this skull faced opponent also appeared in the program when K'Ehleyr used it. Worf defeated this opponent by cutting his upper part of the body. (TNG: "The Emissary")
Jadzia Dax kept a similar Klingon exercise program in the holosuites on Deep Space 9 that also featured this alien. In 2372 she surprised Worf, who used this program and Worf was surprised that Dax was the creator. (DS9: "The Way of the Warrior")