These stamps are created from the very popular The Art of Disney Stamp Collection. There are a total of 4 sets, each highly detailed and converted to a stamp for your Dock. Each set has a theme representing something. This theme represent the Friendship of Disney.The perfect replacement for the Mail app. for Mac users.
Looks like someone already did this set [link]
Take your pick. I personally think you should download theirs since they already it first.