Snails can be nearly invisible to the naked eye or reach more than 1 foot long. They're found in fresh water, salt water, and on land.
They get knocked for their, well, snail-like pace, but it's not like snails can't move at all. Locomotion for most snails is by means of a large flat foot -- more like a body-length muscle -- underneath them that helps them glide across layers of mucus they secrete to smooth their way forward. It will even leave some slime in its wake, if you watch closely for it.
You might be wondering
slow they are. Given it's football season, we'll use 100 yards as a metric. If a garden snail were to receive a kickoff in its end zone and return it all the way for a touchdown, you would have to wait about two hours to see it reach the other end and spike the ball. And garden snails are the absolute speedsters of the snail world!
No Backbone? No Worries! Snail Makes Record First