Yes, I think it's a random event, because I got one the other day saying Dargoryn's chest size had gone up... LOL His treasure chest size...
Well Dickie, most people get implants. Huh? What? OH! You meant the treasure chest! Oops. Well I don't know how, but moonphoenix mentioned it might be a random event.
How do you make your chest bigger?
This is so cool!! I love it guys!!
Yay! At last! I putted my Sheeta's treasure box some items 
. Great idea!
aww,what a lovely ID
Oh boy... now I need to get muffins for Chesid. ^^
Love it! ^.^ goes to put blob dolls into her pets treasure chest YAY!
YAY!
How cute 0
I love it! My galley became small quick when I put in all of my pets' fave items... huggles new feature
I guess it's a random event that gives you more spaces, it gave one more to my dm kora Sika...
Yay!! Happy to have this good feature!
What an extraordinary idea. Sweet and totally original. Congratulations to the person who thought of it and to Keith for implementing it so quickly.
It shows up on your pets information page, if you have items in it
cough Um... dumb question, but... Where is this... treasure chest? Um... I mean... it's not in your userlookup, pets pages, pet information, shops... I mean... is it an item or something?
Oooh! Fun!
Awesome! goes to figure out how it works
If you look at your pets treasure chest, you can remove items from it
Yay! At last the treasure boxes are up 
I love the idea of our pets having a secret stash of goodies. May i ask if you can remove items from a pets treasure chest at all or will it be placed here permenantly?
Hot diggety. (insert thumbs up emoticon here)
Yay it's finally out^.^ lol on what ya did last night keith
Great Idea!!!!!