The tkun was a creature used by the Yuuzhan Vong. A crimson-furred serpent, the tkun was used as an alternative to the coufee when sacrificing a prisoner, functioning as a garrote rather than a dagger. The tkun was able to extend to over twice its normal length and was extremely strong given its small size. During sacrificial ceremonies the tkun would constrict with the beat of a drum crustacean, crushing the victim's throat and suffocating them. It could not be compelled to stop once provoked, and would have to be killed for the victim to be spared. The tkun was a relatively recent addition to the Yuuzhan Vong bestiary, created during the war to fill Warmaster Tsavong Lah's need for a way to make quick, efficient but "spiritually significant" individual sacrifices.
Leia Organa Solo was nearly killed by a tkun used by the Warmaster while on Duro before her son Jacen rescued her.