Dakota Johnson Sent Gallon of Gorilla Poop to Friend's Ex for Revenge

Dakota Johnson’s the queen of savage rid-or-die energy -- because she once mailed a gallon of gorilla poop to her friend’s ex.

Yup, you heard right -- Dakota spilled the dirty tea on Vanity Fair’s Lie Detector Video Series, saying she figured the guy wouldn’t be watching anyway ... so she just confessed to ordering a delivery of some grade-A, stinky revenge.

Dakota said the messy deed went down a few years back ... and when asked where one would even go to cop a similar gift, she didn’t miss a beat -- pointing folks to the website she ordered from, which has since rebranded itself, swapping in the word "poop" for "sh*t."

The actress was low-key impressed with the menu, saying you have your pick of doody, offered in a few different quantities -- the site serves up steaming options from cows, elephants ... and of course, gorillas.

Dakota was even asked if she knew where to order pubic crabs -- and while she swore she hadn’t gone that far down the revenge rabbit hole, she looked a little sheepish … teasing that if she did spill, someone might find out something they really shouldn’t.