Gems

Gems are the main currency in pet tower defence. Its how you hatch eggs. As of update 7 there are 3 types of gems:

Gems
Gems are the first and main currency. It is used to hatch eggs from the normal hatchery.

Dragon gems
Dragon gems are from the event. they can be used in the event hatchery to hatch dragon eggs.

Phoenix gems
Phoenix gems are from another event. They can be used in the event hatchery To hatch phoenix eggs.

Story mode
Gems can be obtained by doing story mode. Every new stage you do you get 20 gems. And each "World" you can obtain 200 gems! (Including hard mode)

Ranch
The ranch is a place where you can go afk to get gems. every 2 min is 1 gem. And with the vip pass you get 1.5 gems every minute.

Event infinite
In dragon gem and phoenix nest you can get both event gems and normal gems (Up to 75 normal gems a day)

Codes
Under the daily quest icon there is a twitter button. In the text box that appears you can type codes to get gems.

Quests
You can get quests. and when you complete those quests you can get up to 20 gems!