Achri, effects are a relatively new feature. They change the look of your pets!
Here is a list of the effects that exist so far:
- Ageless: Ageless pets are just what they sound like -- pets that do not age. You can choose to use this effect to make your pet stop aging as a baby or adolescent. The item that unlocks this effect is the Ageless Extract, an item that was given out in past events.
- Undead: This effect will turn your pet into a creepy, crawly (sometimes) zombie-like creature. Previously available during a Halloween event, it can now be unlocked by using an item called Curse of the Undead to resurrect a pet.
- Stardust: This effect will make your Creatu all sparkly! c: To unlock this effect, you can use a Silver Stardust Urn (for pets from Scria) or a Gold Stardust Urn (for all other pets). This would be a Cash Shop item.
- Cosmic: Somewhat similar to the stardust effect, the cosmic effect will give your pet the appearance of a cosmic, nebula, space-y thing! This effect also comes from a CS item called Cosmic Salve.
- OAK: OAK stands for one-of-a-kind effects. These can be purchased in the Custom Effects section of the Cash Shop. If you order one of these effects, you get to work with one of the artists of Rescreatu to create your very own custom effect that only you can use! Pretty cool, huh?
To look at these effects, please visit the Creatu Directory (http://www.rescreatu.com/petinfo/) and choose an effect from the drop-down box. Only certain effects are available for certain pets, so you'll have to do a bit of browsing.
Let me know if you need anything else! :)