Being very high in this (for a fruit) has given avocados the nickname "butter pear"
... Avocados are the only fruit high in monounsaturated fat, the premier fat 
for... [DOC] [TLE] Fruits for beginners - Hein Bijlmakers [PAR] Avocado pear, Butter pear, Alligator pear and Midshipman's butter.