What is Clamcoin?

CLAM is an innovative decentralized payment network and a new digital currency that is a variations of the original bitcoin code.
You can read more at the Official Site
(http://www.clamcoin.org/)

Where do i get it?

If you held a balance on May 12th 2014 in a BTC, LTC, or DOGE address then you most likely already have CLAMcoin, it was distributed over three million 'accounts' at its creation.

You can not mine them like other cryptocurrencys, instead you have to Dig them. (Rather suitable term since its a Clam :-))
To see if you have any follow the link
(https://freebitcoins.com/clamchecker/dig_wallet/)

You can also use the Clam Client and earn Clams with it. Approximately once per minute, the network automatically selects one running unlocked client to process recent CLAM transactions, rewarding them 1 CLAM. To do so follow the link
(http://clamclient.com/start/download/)
or
(https://github.com/nochowderforyou/clams)

Finally there's also a Faucet that distributes Free Drops (that means 0.00001000 Clam)
Here is the link for the Faucet
(https://freebitcoins.com/ask/)