Thumbelina carrots are a unique variety of heirloom carrots known for their short, round, and stubby shape, resembling small orange orbs. They typically grow to about 1-2 inches in diameter, making them look quite different from the traditional long, tapered carrot. Despite their small size, Thumbelina carrots have a sweet, crisp, and tender texture, with a flavor that is often described as richer and earthier than standard carrots.