Thumbelina, the world's smallest horse visited patients at the UK Children's Hospital on Thursday afternoon.

Thumbelina travels in style in the ThumbyMobile. At just over 17 inches tall, the miniature horse is more inclined to walk under fences than jump them. Her owners have sheltered the mare from ever gaining "circus-sideshow" or "one-trick-pony" status.

As the world's smallest horse, 5-year-old Thumbelina, weighing in at 57 pounds, has a bigger mission: to raise $1 million for children's charities this year. Thumbelina will visit sick and needy children across America.