neopetsinfo.net

Here is a list of neggs and their effects.

Negg	Cost	Effect
Basic Power Negg	39 Tokens	May give you 1 defense.
Blue Furry Negg	15 Tokens	Will give your NeoPet 5 HP.
Bang Bang Negg	33 Tokens	Gives your a random snowball or snowballs.
Cackiling Negg	96 Tokens	In the battledome it gives shadown health ability in the battledome regardless of your NeoPets level. (single use)
Christmas Tree Negg	27 Tokens	Will give your NeoPet 20 hit points back.
Confusion Negg	64 Tokens	In the battledome it gives your NeoPet Phsycic Powers or the ability to confuse in the battledome regardless of your NeoPets level. (single use)
Cool Negg	247 Tokens	Gives your NeoPet 1 level and 1 strength, or movement, or hitpoints. (only gives 1 of the 3)
Cracked Negg	90 Tokens	In the battledome your NeoPet gets +3 DMG or +3 HP or random full healing. (single use)
Crystal Negg	22 Tokens	This negg will give your NeoPet back 8 HP.
Evil Negg	42 Tokens	This is a battledome weapon that attacks 2 dark and 1 physical icon. (single use)

Throughout neopets you will be able to buy and even find some mushrooms. Depending on the kind of the mushroom, you may get good or bad results from feeding it to your pet. Here is a list of results from each mushroom.