Here are a couple of Mario Mushroom hats I made just before Christmas. You can find the pattern for free here on Ravlery.
The hats are done in the round but they join at the end of each round. I made the red hat this way but didn’t like the join showing on the hat so when I made the green one I didn’t join, I just kept going round. It turns out the green one came out a little bit smaller than the red one. I’m not very savvy when it comes to altering patterns so I had no idea it would do this but I guess it’s nice to learn these things.