Serpent worm

The serpent worm was a lifeform that served as the main ingredient of gagh, a Klingon delicacy, as well as of bloodwine. (TNG: "A Matter Of Honor"; DS9: "Sons and Daughters"; LD: "A Farewell To Farms")

On Qo'noS, they were typically bred beneath the soil on farms (with a similar layout and appearance to an Earth vineyard). To harvest serpent worms, a sprinkler system is activated above the soil in which they live, which drew them to the surface. (LD: "A Farewell To Farms")

In 2373, serpent worms for gagh were delivered to Deep Space 9, where the tentacle of a creature grabbed Kira Nerys' hand. (DS9: "A Simple Investigation")

Ma'ah's family owned a serpent worm farm and had raised them to produce bloodwine for generations, where he was forced to work when he was relieved of command from the IKS Che'Ta'. (LD: "A Farewell To Farms")

According to Klingon for the Galactic Traveler by Marc Okrand, and according to the video game Star Trek: Klingon, serpent worms are referred to as "ghargh" (or "gharghmey") before being prepared into gagh.