What Kirby is made of

Kirby is usually referred to as "The Pink Puffball", which may be a hint. In the anime this subject was brought up in episode "The Big Taste Test", and Kirby was once believed to be made of Zenbon, but was later proved false. Other than this, what Kirby is made of has never been mentioned in the games or anime. On the other hand, INSIDE Kirby is believed to be a colossal area of hammerspace, which takes a striking resemblance to deep space, this is seen multiple times in the anime.