Anvil

Anvils appear in the game Bean Counters, being thrown out of the truck. If you are hit by one, you lose a life.

Anvils also appear in Jet Pack Adventure tied to blue balloons.

Trivia

You used to be able to get the anvil pin for 2 weeks in the Boiler Room.
Anvils appear in some parties.
There is a contraption called the Anvil Maker 3000 which makes Anvils.
File:Anvilpin3.jpg
The Anvil Pin.
During the Medieval Party 2009, there were Anvils at the Dock.
If you wear a blacksmith apron and start dancing, you'll start hitting an anvil.
There is a comic on community.clubpenguin.com/comics, and its name is Anvil Counters, which is about anvils being thrown out in the game Bean Counters, and anvils are mentioned in another comic called "No Anvils??", which is about a penguin complaining to a barista of the Coffee Shop about having no anvils to go with his coffee.
The item ID for the anvil pin is 611.

In Bean Counters (As an obstacle).
In Club Penguin as a pin and cloud.
In both Medieval Parties.
In the Dance Lounge at the Dance-A-Thon Party.
One of the clouds made by the Cloud Maker 3000 in the Festival of Flight 2009 was an anvil.