Some guy found a frog in his lettuce (alive) a few years ago and kept him as a pet.

from the article:

...news outlets reported on 40 unique incidents of people finding frogs, birds or rodents in bagged/boxed greens between 2003 and 2018.

Amphibians and reptiles (tree frogs, toads, lizards and snakes) accounted for 30 of the 40 incidents and most of the critters were dead, with a few being alive. The rest were other types of animals (birds, rodents and bats).

very sad but at the same time, imagine finding a snake or bat in your mixed argula or whatever