Throw the snail away asap.....
I had one small innocent looking snail and all of a sudden there was like a thousand of them. ( I mean it -1000) . My axie got sick for 2 weeks after the snail attack. I had to change most of the water twice in one week, take out the sand- put it in the sun, fish out the snails one by one.
They put the ammonia levels of ur tank out of control so ur axie will get sick if you leave it. I d rather kill one snail than let my axie die.
Even like two months later I still get some snails coming out from nowhere.