If you visit Pong and Perdita at the Dalmatians’ House in Traverse Town you’ll learn that their 99 Dalmatians have gone missing. Throughout the course of the game you’ll be able to find them in chests (because that makes sense) and for every few that you collect (they come three at time) you can check back in for a reward. Rewards are cumulative so if you wait to collect them all before checking in you’ll still get everything.
Mythril, Torn Page
Complete gummi collection, Aeroga
Where are they?
If you followed the walkthrough you will pick all of them up. If not, consult the table for their locations.