The thaumic chronometer is a rare prize from the Squeal of Fortune, obtainable only between 6 September and 16 September 2013. It is used to make a golden chinchompa hungry, and remain that way until it has eaten ten meals, in order to speed up growth of the pet. When used on the chinchompa, it gives the following message: "The magic in the thaumic chronometer means your chinchompa will remain hungry for several feedings in a row." This item can only be used once and then it disappears from your inventory.
As Golden Chinchompas have now been removed, upon destroying you may now claim 500 gold when prompted.