There are plenty of fruits that can be poisonous and dangerous to our health if eaten improperly. Certain fruit peels are difficult to consume and at times are also inedible and poisonous. For example, peels of avocados, honeydews, melons, lychee, pineapple and the likes are considered as inedible. Talking about being poisonous, mostly it's not the peels rather other aspects like seeds of the fruit, ripe or raw fruit, etc. that one needs to worry about. For instance, seeds of apples, apricots, cherries contain amygdalin, which after coming in contact with acids in human digestive system becomes cyanide. Similarly, cashew fruit, almonds, etc. should never be eaten in their raw form.