I bought the Leap Frog Fridge Farm Magnetic set to keep my daughter busy while I was in the kitchen. The set comes with a magnetic reader and ten magnetic animal halves which fit in the reader. When an animal is placed in the reader, it says "purple cow" or "yellow duck" (or whatever animal is placed there). When the rear and head halves of the animals match, the unit cheers. When they are mismatched, the unit invents a silly name for the creature they've created.
It has a Spanish option, so occasionally instead of "yellow duck" you'll hear "pato amarillo."
I like the idea of the fridge farm, but mine has never worked properly, so I have rated it low on durability. It is also difficult for younger children to know the rear of the animal goes on the right, and the head goes on the left.
I also have the Leap Frog Magnetic Alphabet set, and recommend like it a bit better than the farm set.