Ligorian mastodon

From Memory Alpha, the free Star Trek reference

Ligorian mastodons are large animals which are invisible.

In 2373, Jadzia Dax compared the Jem'Hadar's tracking of the cloaked USS Defiant through the Badlands by the ionization of its warp engines to the passage of a Ligorian mastodon through the forest: it can't be seen, but it makes the leaves rustle. (DS9: "Blaze of Glory")