Sundance is an Earth pony and Megan's one special pony. She's a tad klutzy, but is a really good jumper (though she has trouble landing).
She's more or less the star of Escape from Catrina. She nearly drowned Baby Moondancer, ruin a banner, and catapult a unicorn and Spike through the air into buckets of paint. Her time came when she saved Baby Moondancer from Catrina with her excellent jump.