Judas goat

American  

[joo-duhs goht] / ˈdʒu dəs ˌgoʊt /

noun

1. a goat that has been specially trained to lead sheep or other livestock, especially to the slaughtering place in a stockyard or meat processing facility.

   Some smaller meat packing plants still use Judas goats.

   Instead of opting for Judas goats, his farm uses the most responsive cow in each pasture group to drive the others when it’s time to move.

2. a goat, fitted with a radio transmitter, that is released in an area to find and join a herd of wild goats, guiding conservationists to their location by means of the radio signal: used to control populations of wild goats considered invasive and destructive.

   The park currently serves as home to three Judas goats—agents of an effort to protect the local ecosystem.

3. a person who betrays followers or dependents, often unwittingly as the tool of an enemy.

   Some say the leader of the union is a Judas goat, far too cozy with management and making too many compromises.

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Etymology

Origin of Judas goat

First recorded in 1905–10

Example Sentences

Campbell’s Ph.D. project was the development of the Mata Hari goat—a variation on the Judas goat, which was developed in the 1980s.

From Scientific American

Reviled by old allies on the right — “Judas goat!”

From Los Angeles Times

Judas_Goat well had the security guard not WWF off-the-rope-tackle-slammed the fan, the piano wouldn't have fell over. all the fan did was hug Bieber. all the security guard had to do was kindly escort the fan off the stage. all that tackling he did was excessive and unnecessary.

From Time

"S�," he says at last, and the word sets in train the strange and affecting tale of this strange and brilliant Italian film, the hilarious and horrifying parable of a Judas goat who innocently leads a lamb to the slaughter.

From Time Magazine Archive

As a part-time historian I can tell you there's a word for that—Judas goat.

From Project Gutenberg