Eel-bird
From Memory Alpha, the free Star Trek reference
The giant eel-bird is a creature native to the planet Regulus V. The eel-bird must return to the caverns from which they were hatched every eleven-years in order to mate. Like the salmon, Spock refers to the eel-bird while attempting to explain the Vulcan mating ritual pon farr. (TOS: "Amok Time")
