Either way.
It will fill out more if you leave it.
You can cut it and loosely rubber band it to something like a rock or plug. It will attach in a week or two. Then you can move it or sell it when it gets bigger.
Toads are hardy. You can cut the head off and a new one will grow.
If you try to pull it off of the rock and speck left will grow into a new toadstool.
Keep it trimmed up. When it gets bigger cut it like cutting the crust off of a pizza. Those pieces will grow into new toadstools too. Or just toss them.