Lawn Ninja 

A small Gnome-like creature from the Ratchet & Clank video game series. Highly annoying and carries twin swords that it tries to cut your crotch with.

John: Nice hair.

Jane: Freakin' lawn ninja!

Lawn Ninja by Xalrons456 March 26, 2012

Guatemalan lawn ninja 

The unidentifiably Hispanic lawn maintenance crew. They mysteriously appear at 10am on a Saturday, with neither call nor contract. They set up all their equipment and wake you up with their obnoxious weed eaters, but manage to disappear before you are awake enough to open the blinds.

*covers face with pillow* Damnit honey the Guatemalan lawn ninjas are back!

Guatemalan lawn ninja by Jacki B February 21, 2009

Ninjas on the lawn 

Along with paranoia, ninjas-on-the-lawn is the most common side effect of cocaine.

asshole: "What is that outside?"

you: "I'm not sure, but i think it could be NINJAS."

asshole: "There are no ninjas on the lawn."

you: "OF COURSE THAT'S WHAT THEY WANT YOU TO THINK; THEY'RE NINJAS."

Ninjas on the lawn by SnowhuouV October 24, 2012

there's ninjas on the lawn 

Its a less racial way of saying there are black people somewhere on your property. We say it when blacks show up at our haunted house. The blacks are usualy the ones that hit our monsters and get all kung foo on that ass when they get scared. So when they show up, a call goes out over the radio that "there's ninjas on the lawn"
I have also used it when there are black ppl around my store. Like when they hang out in the parking lot doing nothing.

I saw a group of black people headed for the entrance to our haunted house, so I alerted the managers that there's ninjas on the lawn.

there's ninjas on the lawn by Russ Bus January 9, 2008