Gunji jackdaw

From Memory Alpha, the free Star Trek reference.

A Gunji jackdaw is a large, emu-like bird.

A resident of Deep Space 9 dreamt up a pair of Gunji jackdaws when everybody's dreams (and nightmares) became the truth in mid-2369 when the station's inhabitants were studied by an advanced alien species. Odo had to herd the two jackdaws safely through the promenade. (DS9: "If Wishes Were Horses")

In actuality, the Gunji jackdaws were "played" by emus.