A camel was a humped mammal native to the Asian continent of the planet Earth. Camels were often used as beasts of burden in the desert regions of the planet.
After Captain Jonathan Archer restored a damaged timeline in 2154, camels passing by the pyramids of Egypt could be seen in the timestream as the timeline realigned itself. (ENT: "Storm Front, Part II") The Guardian of Forever showed a similar scene to the crew of the USS Enterprise in 2267. (TOS: "The City on the Edge of Forever")
Doctor Sigmund Freud kept a small statue of a camel in his office. (TNG: "Phantasms")