It is the Kingdom Key from the Kingdom Hearts game series. It is large enough to swing around like a real sword, but I do not know if it is truly life size because I do not know what the canon size of the Kingdom Key is.
It is quite a remarkable piece, but it does have two minor flaws -- the yellow guard is not welded or otherwise fastened in any particular position and rotates freely. Secondly, the chain on the end with Mickey Mouse's head on it is extremely long. Recipient may of course modify the prize as they wish.