“When you don’t know whether or not someone is eating something, are they omnomymous?”

“Nom nom” is the sound of that the Cookie Monster Muppet character from the children’s television show Sesame Street makes when he eats. “Omnomynous” (or “omnomymous”) is a portmanteau of “nom nom” and “anonymous.” “Omnomynous”  (or “omnomymous”) also sounds a bit like “omnivorous” (eating both plants and animals).
         
“I’m going to choose food critic as a backup career, with the alias ‘Omnomymous’” was posted on Twitter by Jackson T on February 15, 2012. “I want to go out to eat with a bunch of friends wearing Guy Fawkes masks. We will call ourselves Omnomymous” was posted on Twitter by Chelsi Craig on November 14, 2012. “When you don’t know whether or not someone is eating something… are they… omnomymous?” was posted on Twitter by KiKi Senchou 🔞(Egg Queen) on September 17, 2021.
   
“A person with no face, no name, that loves to eat… OmNomynous…” was posted on Twitter by Cleave on September 4, 2020.
   
“What do you call someone who eats food secretly? Omnomynous” was posted on Reddit—3amjokes on May 22, 2022.
   
   
Urban Dictionary 
nom nom nom
Represents the sound made when someone is eating or chewing something and really enjoying it.
“Hey, are you eating my brownies?”
“Nom nom nom.”

by Zig Awesome July 2, 2007
   
Urban Dictionary 
nom nom nom
The sound made by the cookie monster from Sesame Street while he is eating his cookies.
Cookie Monster: Oooh Cookie! Nom nom nom!!
by Enips4evar December 10, 2008
   
Twitter
Jackson T
@TheJacksonT
I’m going to choose food critic as a backup career, with the alias “Omnomymous”
8:48 PM · Feb 15, 2012·Twitter for iPhone
   
Twitter
Chelsi Craig
@ChelsiCraig
I want to go out to eat with a bunch of friends wearing Guy Fawkes masks. We will call ourselves Omnomymous.
9:58 PM · Nov 14, 2012·Twitter for iPhone
 
Twitter
Cleave
@InkDragonWorks
A person with no face, no name, that loves to eat…
OmNomynous…
5:11 AM · Sep 4, 2020·Twitter Web App
     
Twitter
KiKi Senchou 🔞(Egg Queen)
@KikiSenchou
When you don’t know whether or not someone is eating something… are they… omnomymous?
7:15 PM · Sep 17, 2021·Twitter for iPhone
 
Reddit—3amjokes
Posted by u/UnfortunateHyrbrid May 22, 2022
What do you call someone who eats food secretly?
Omnomynous