It is a red crown with an amethyst on top.
Nintendogs + CatsEdit
It is a red crown with emeralds on it and a single emerald at the top. In Nintendogs + Cats, it can be bought from the Seaside BARC for $1,000 once it has been unlocked with 10,600 Owner Points or by playing for 33 days.
DS: "With this impressive crown, your puppy can rule the kingdom every day."
3DS: "This royal crown is perfect for the king or queen of your home."
- DLC neighbor H Hoover's German Shepherd King Tut can be seen wearing a Crown.