look up any word, like donkey punch:
 
1.
The cool way of laughing; the way Peter Griffin laughs on Family Guy.
Nyahaha, sweet.
by Spike9123 March 20, 2004
 
2.
Laughing like a Japanese cat person also known as a "Neko"

Neko's are seen in Japanese Anime
Person 1: *Says a funny joke*

Person 2: Nyahaha!
by DudeRicky0253 January 08, 2012
 
3.
1: the 'cool' way of laughing. The way Peter Griffin laughs in Family Guy.

2: Something Hootowls say. They say this because once, in a concert while performing "Alligator Sky", at the end of the song, Adam (if you do not know who this is, you obviously didn't click on Hootowl ) made an inhuman (adorable) noise that is believed to be spelled "Nyahaha".
1: Nyahaha, that's cool.

2: OMG I love Adam so much!!! LOL NYAHAHA
by LittleOwl1226 February 27, 2012