Dirk: Me neither. We're both starving equally.
Arthur: Look! A whole cooked chicken with side of mashed potatoes and a warm/soft dinner roll!
Dirk: We have to decide which of us gets to eat first. To be fair, we should rock-paper-scissors for it.
Arthur: Om nom nom nom nom!
Dirk: Arthur, you're a jerk. A real knee-biter.
You can "om nom" on things besides food... for example, play-eating babies' toes to make them laugh.
omnomnomnom (dot) com is a pop culture website where people submit their own silly photos that have been manipulated in Paint to resemble monsters eating various things, including people and pets.
May be colloquially referred to simply as "oms".
Billy: Let's book it to the 7-Eleven to get some omnoms then.
Joe: These bbq kettle chips are fucking delicious.
Susie: I know, they're my fave type of oms.