On wombats:

Despite the fact that they do not look streamlined, a wombat can run at up to 25 miles an hour, and maintain that speed for 90 seconds. The fastest recorded human footspeed was Usain Bolt’s 100m sprint in 2009, in which he hit a speed of 27.8 mph but maintained it for just 1.61 seconds, suggesting that a wombat could readily outrun him. They can also fell a grown man, and have the capacity to attack backwards, crushing a predator against the walls of their dens with the hard cartilage of their rumps. The shattered skulls of foxes have been found in wombat burrows.