When a Baby animal becomes an Adult, its Mature parents become Elder Animals that will be automatically sold for Elder Animal Points.
Check out the GIF below for the Elder Animal Points demonstration.
You can also visit your Animal Collection to check how many Elder Animal Points you can earn when your animals become Elders.
Tap the type of animal that you want to check.
Then select the exact breed from your collection.
You can view the Elder Animal Points you will earn by selling Elder Animals.
When you have enough Elder Animal Points, you can purchase Elder Animal Prizes from the Merchant.