Tinder Ninja 

A person of male gander who makes a somewhat fake rinse profile to meet women to just sleep with them only performing the Ninja sexual and then disappearing from their lives forever into the shadows.

All of a sudden, all of the local girls have become pregnant. Officers suspect an ultimate tinder ninja.

Tinder Ninja by wnigwigga July 12, 2016

slick ninja 

Stealthy and sly.

Banksy is one heck of a slick ninja with the way he puts up Street Art.

slick ninja by DolinDog June 8, 2016

Penis Ninja

An assassin who uses stealth and guile to assassinate a penis, often causing death to the owner of that penis. Scissors, knives, razors, and fire are typical weapons of a penis ninja. An historical example of a penis ninja would be the woman who killed Genghis Khan by slicing off his royal penis. Lorena Bobbitt is a more modern penis ninja of note, although her intended target managed to survive and was reunited with it's body.

I found out Jasmine carries a tanto knife in her purse. I hope she's not a penis ninja.

Penis Ninja by Flavius Schmoesephus December 12, 2016

Playing Ninja 

When two men go to one's house, and start jerking each other off

Hey, do you want to come over and start Playing Ninja.

Playing Ninja by Bigmike6726 March 17, 2017

Brush Ninja 

A person (usually a hiker) who goes where they please, sneaking though the brush on private property to get to their destination.

David's a brush ninja, he cut through that farmers land to get to granite mountain.

Brush Ninja by hiking guy March 19, 2017

shadow ninja 

He is stealthy, magic, majestic

that horse is like shadow ninja

shadow ninja by kayden omniverse January 13, 2018

Nostalgia Ninja 

Something from the past you never knew knew existed, but realize as an adult you know everything about them.

Air Supply? Never heard of them. Oh, yeah, I recognize that song. Hey, I know all the words to this one. Wait, I know that one too. Holy crap, they also sang this one?! How do I know all the words of 11 of their songs and never knew who the hell they were?!?! That snuck up on me like a nostalgia ninja!

Nostalgia Ninja by Geo October September 7, 2018