Kat

 the Pet Sitter is a NPC who resides in the Pet Shop at. She will look after Pets and after a certain amount of time, the rarity of the pet will be upgraded. The cumulative experience of the pet will remain the same, but the level will be adjusted because higher rarity pets level up slower due to needing more experience per level.

Players can leave only one pet with at a time.

Every pet has different time and costs to upgrade to their next rarities. For example, an Wolf Pet takes 5 days to upgrade to, but a  Blue Whale Pet takes 7 days to upgrade to.

Pet sitting requirements
Leaving higher rarity pets with requires progress in the Taming skill. (Can vary between pets with the same rarity?)

Calculator
Assuming that the factor is the same for all pets the cost is calculated as follows:


 * $$\text{cost} = \text{base price} - 0.3% \times \text{pet level}$$
 * $$\text{cost} = \text{base price} \times (1 - 0.003 \times \text{pet level})$$

"Base Price" in the calculation / calculator is based on the value in the table listed below

To get the base price for a given pet you can calculate:


 * $$\text{base price} = -\frac{1000 \times \text{cost}}{3 \times \text{pet level} - 1000}$$

Base Price Table
The following table contains base prices as well as prices for unknown levels. Please correct the prices for unknown levels (marked with NBP). You can use the base price calculator from above.

For any price without NBP, you can assume.

Time taken also lowers per level, though the amount is unknown.

Dialogue

 * Hey! I'm Kat the Pet Sitter!


 * While you're busy adventuring I can take care of your pets.
 * I might even be able to train them to become stronger!

Trivia

 * The skin used for is a reference to Serena, the deuteragonist of the anime Pokémon X/Y, and the female protagonist of the games of the same name.
 * The only pet that cannot be upgraded by Kat is the Griffin Pet which requires the use of a Griffin Upgrade Stone.