We play a lot of hide and seek these days, and Ethan will often hide.
The rules are: you have to look around for Ethan (this can be done sitting on the couch) and verbalize where you’ve looked. Is he under the coffeetable? No. Is he under the chair? No. Where could he be? Where’s Ethan? Ethan will slowly come out of his hiding spot (see above), and the longer you pretend not to see him, the harder he laughs when you finally do see him and are startled by his presence.