humm if his own toys are not amusing, and it sounds like finger-painting might be out,
try bringing out the pots and a ladle.( If he is more precocious than that put his toys in the pot cover with a lid and have him uncover them.) Big boxes are fun too. Picture books and asking questions about shapes, colors and animals. Pushing a ball back and forth is fun and a carefully watched bath with not very much water is fun too. Watch out for those floaties though. The brown ones.
