I stepped on a stone fish or a catfish years ago, never actually saw it, but from the intense pain, the locals were saying it didn't matter which it was, what mattered was to get to a doc asap.
The doc gave me a jab and three different kinds of pills, along with a cream. Didn't stop the pain any though, it was excruciating.
Since we get pretty low tides every now and again and we surf in a sometimes muddy spot, my second trip to that doc is just a matter of time, I suppose

I also had the eel thing happen to me; as soon as I put my foot down coming back in from a surf, I stepped on what I thought was a piece of garden hose, until a second later it slithered from under my feet! Ugh!