Carrie Underwood had a blast taping her guest role on CBS' How I Met Your Mother last week, and her character got into some really fun situations on the show. Carrie writes on her blog saying, quote, "I got to...dress up like a flight attendant, play a cavewoman, and had a baby pig poop on me...jealous?" Carrie plays a pharmaceutical sales rep named Tiffany who is also a love interest for the show's character Ted, played by Josh Radnor. Look for her episode of How I Met Your Mother to premiere in March.