This is not the first time that ThinkGeek have released a free t-shirt and as usual there is a catch. And that catch is that in order to get the free tee you must first spend $40 and then add this item to your cart. Or you can add this item to your cart and then add $40+ dollars of other items to your cart afterwards. You probably get it.

Note: This item is available only while supplies last. Sizes not listed are sold out. Sorry, no returns or exchanges.

As you can see, this is a Big Bang Theory design mashed up with the Legend of Zelda, which I think is quite an approprate mashup.

Link: ThinkGeek