Code
sprite = Sprite('Tobi')
import time
sprite.setrotationstyle('left-right')
while True:
sprite.move(5)
sprite.bounceonedge()
sprite.switchcostume("Tobi walking 1")
time.sleep(0.1)
sprite.move(5)
sprite.bounceonedge()
sprite.switchcostume("Tobi walking 2")
time.sleep(0.1)