Found these little critters living in some lettuce growing in our backyard garden. There were a few dozen floating in the water after washing the leaves for dinner. Any ideas what they are?

This is a close up of the main body:

This looks like the tail section:

This looks like the head:

This is an overview of as much of the critter as I could fit in the frame

Excited to share these first pics from my new Foldscope 2.0. Pictures 1,2 are 140X and 3,4 are 50X