Answer:
What has roots that nobody sees, and is taller than trees. Up, up it goes, and yet it never grows.
What has fingers and a thumb but no hand?
What has one head, one foot, and four legs?
Humans have two that shrink in the light and expand in the dark
What is something you can give away as many times you want without ever losing it?
Special abilities and brightly colored underwear are all you need to be one of these.