#zer0 headcanon

I mean, why give them a bunch of sharp teeth and these cool palps and mandibles if they’re not gonna use them in a very edgy desperate act of lethal self defense after getting their face all messed up? 
(Most of that isn’t their blood but also they pass out like ten seconds later.) 

“Of course I can smile / I definitely know how.” They open their mouth and squint real hard. “See? I’m showing joy.” 

Since people liked my Zer0 headcanon here’s some more features (admittedly, I’m still not totally consistent in how I draw them)? 
Their upper “lip” can only really pull up into a snarl but their mouth is at least permanently curved upwards so they can approximate a smile. 
The upper pair of  appendages are akin to palps, the lower are another set of “jaws” (kind of like what moray eels have, except on the outside, and like, way more mobile.)

Their actual lower jaw also splits apart but that makes for a pretty terrible smile.