I hope this isn't illegal to post this here. :)

I've had so many weird bugs/worms show up in my garden this year. But this question involves a slug-type worm that is climbing out of one of my stock tank water gardens. I was growing marginals in this tank, when it sprang a leak and the water level is lower. I think a deer munched on the Pickerel rush and ruined it, plus duck weed took over the surface. I left it all 'cause there's tadpoles in there. Anyhow..........I saw this worm crawling out of the water this morning (saw it after it climbed up). I don't see any antennae. Any idea what it might be?

Thanks!