om nom nom

The story

Onomatopoeic, attested in 2004, variant of num-num. Originally from the sound Cookie Monster on Sesame Street makes when he eats (from late 1960s and early 1970s), though this was canonically “un num num num num”, with a ‘u’. Popularized since 2007 in Internet use, particularly in meme-based images, especially lolcats and other image macros. See nom for details.