From the book itself:

Aiboh (the Spherical Sprite)
Biome: Tropics
Diet: Mainly nuts
Aggressive?: No
Rarity: **
Type: Fauna (Fey)

"Known by locals of Nax Island as the "coconut fairy", aiboh are beyond extremely shy. In fact, I only befriended Albert (my aiboh) by giving him exactly fifty-five (55) coconuts (for some unknown reason, aiboh prefer to eat coconuts five-at-a-time, and no fewer or more than that)."

So, there's just enough pages in the book for one monster to represent each letter of the alphabet! Simply put, aiboh are coconut fairies, living mainly on those things, but sometimes eating other nuts. Read above for more info!

And yes, that is a Tamagotchi holding the page down (an Angel one, to be exact) XD