mouth maggots

These are window warriors who talk tough but can't back it up.

He said he would kick ass? Hahaha Bahahaha, he is just got mouth maggots!

Maggot Mouth

Someone who unnecessarily talks shit about people to make themselves feel better, even though they themselves are just pitiful and begging for attention.

"Did you hear all the shit that guy is talking?"

"Oh yeah, he's such a maggot mouth. Ignore him."