Sweeper Trees, Slippery Swing Set and the Scary Go Round are three of the wild and crazy new obstacles that contestants, including a skinny med student and a 58-year-old grandma, will face on this week's episode of "Wipeout."

This week a special "Wipeout" "All-Star" episode features former fan favorite contestants Ariel "Never Been Kissed" Tweto, "Go-Go Dancer" Jesse Duran, "Muddy Beard" Keith Biondi and "Super Stu" Yasutake, who all return to face off for a second chance at $50,000.