Answer:
When it comes in, From sea to shore, Twenty paces you'll see, No less, no more.
My first is a creature whose breeding is unclear. My second, a price you must pay. My whole can be found in the river of Time and refers to events of today.
Whoever makes it, tells it not. Whoever takes it, knows it not. And whoever knows it wants it not
Long and slinky like a trout, never sings till it's guts come out.
Hands she has but does not hold. Teeth she has but does not bite. Feet she has but they are cold. Eyes she has but without sight.
You use it between your head and your toes, the more it works the thinner it grows.