Let's not be one...okay?

Fuckweasel (noun)

A shifty, scheming person that will do whatever they need to do to escape whatever they fear in the moment. In Internet forums they are often regarded as a fake, a poser, or a liar. They often attempt to extract information from you to share with others and/or use it against you. A Fuckweasel often uses shiftiness to evade an obligation, commitment or responsible duty.