When we were in Nebraska, Isaac played with all of his buddy Jake's toys. One of his favorites was an oinky pig, a latex squeaky toy that, instead of simply squeaking, oinked like a pig. He liked it so much we went to Walmart to buy him one. Well, actually, we bought two, in case he killed one.
He loves it and immediately learned its name. Tell him "Get your pig!" and he runs to get it. The only other toy he regularly fetches by name is his Kong. Anything else is just "Toy."
He adores the oinky pig. This may be the best $4.97 I ever spent on him