Stealth pig 

A person that is walking down the street
Looks awesome from behind

But as you pass them and look closer total pig

O look at her awesome

O shit total stealth pig

Stealth pig by Captaincaveham December 16, 2018

Stealth Pig 

A person who attempts to appear as if they are refined or otherwise proper when they are in fact promiscuious or a sexually aggressive predator.

Don't trust John he may seem like a nice guy but he really is a stealth pig.

Stealth Pig by Nitek July 16, 2011