Nature Calls - S1.E8

Keo and Lemony worry after Yakkity fails to show up and perform at a kids' birthday party and at the school's football game. When they look for Yakkity they find him on top of the water tower with a giant pimple. They discover that Yakkity's strange behaviour is the result of some changes that yaks experience when they get older such as breaking out, constant sweating and the urge to reach higher, cooler areas to escape from the heat.