This weapon is very similar to a real-life air powered tranquilizer gun. It is white with orange zebra stripe patterns on either side, and has an open chamber located on top that can load and fire one dart at a time.
When Nick Wilde hides from Judy, Judy is able to detect him with her sharp hearing and fires an elephant tranquilizer dart at him. Nick then falls to the ground unconscious, with the dart in his rear end.
As she writes Nick a ticket, a wildebeest comes by and, mistaking the dart's green stabilizer for a tuft of grass, eats it, and then collapses under its effects.
While chasing Nick through Little Rodentia, Judy aims and fires the gun at him and the dart misses.