Nyehehe 

A dirty laugh typically used by someone who is in a state of intoxication. Usually used after an inappropriate comment.

What up ladies, wanna touch my penis nyehehe?

Nyehehe by Jonastybut December 20, 2010

Nyeheheh 

An interjection made popular by a magic skeleton named Papyrus in the game Undertale, made by Toby Fox

Papyrus: NYEHEHEH!

Nyeheheh by Riikaaz Dinok October 5, 2018

nyehehehe 

A particular laugh made by Papyrus in the game Undertale.

Also, an 'evil' type cackle.

Sans: I bought more spaghetti
Papyrus: NYEHEHEHE YES

nyehehehe by meep meep motherfluffer June 5, 2016