Freaky snail situation
 

I noticed little bumps on the shells of my two big turbo snails but figured they were just some sort of filter creature. Then, I thought these bumps were moving, but dismissed it as my bad eyesight. So I was peering into my tank at a random hour in the middle of the night as I like to do, and got a good look. Turns out the bumps do move, and they are babies of varying sizes that are just smooching off their parents. Pretty freaky looking as there are multiple mouths, antennae, whatevers all moving around in a squishy way. The biggest "baby" also lifted it's shell and I saw what looks like a bunch of eggs? What the hay? Can't find much info on this online.

Weird!! What kind of snail is that?

I think it's a turbo? It's a good size, been in my tank for about a year. I haven't read anywhere that they carry babies on their backs.
Here's a side view

I'm with you! Looking at it makes it look like they are definitely riding on the back. I know before o transferred my tank over I had a bunch of babies but they were just on the glass of the overflow.