The problem it presented was that our round potty seats from Target don’t fit right–they are more for round toilets, and this toilet is more of an oval shape and sticks out more…so the old seats slide around.
I looked around the internet for a low-cost, fun potty seat and I found this one. I got it today and it works great. This seat is made mainly of hard plastic (no cushion) and rubber. I think these are both pluses since the rubber keeps the seat from moving and the hard plastic doesn’t have any crevices that are difficult to clean. (Update 6 months later: This seat still is in pretty good condition. The eyes have peeled off, but otherwise, it is in very good shape. I still recommend this seat)
So if anyone else is having this problem, this is the seat for you: