Answer:
A pony trots his way through the world on these.
John Lennon sang about being this toothy creature.
What has no arms, hands, or legs but moves the earth?
The strangest creature you'll ever find: Two eyes in front and many more behind.
Which bird does not belong in this group? Finch, gull, eagle, ostrich, or sparrow?
What an fill a room but takes up no space?