go hog wild

Become crazy with excitement, as in The crowd went hog wild as soon as the band began to play. Why this expression should allude to the craziness of hogs is no longer known. [Colloquial; c. 1900]

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.