The 'frisbee' quality of biscuits is determined by the nature of the top surface. In scientific tests, smooth-topped Rich Tea scored the longest distance, and Lincoln showed the greatest lift, due to the vortices created by the regular pattern of knobbles on the top. Maryland Cookies will not fly.
The three-toed sloth actually has four toes, one on each foot, but as they fall off regularly and are regrown, the typical sloth only has three toes at any one time.