A monkey is a creature that has been compared to humans in many ways for a very long time and it is because of how much they physically resemble humans. Science has been divided on how monkeys should be accepted and whether or not they deserve to be counted as our true relatives.
To dream of a dead monkey means that you are no longer as stubborn on some issues as you used to be. Monkeys are known for being extremely stubborn and hard to deal with because of how annoying they can be and how unresponsive to direction they are. If you dream of a dead monkey then it means that you are through with being more stubborn, you are now a much more flexible person and know how to roll with the punches when necessary. This could also mean that you have become a generally nicer person. You were not as nice before but now you have learned a lesson and have learned to be a bit nicer rather than such a monkey.
A dead monkey can also represent a more wild side of you. A monkey is a creature that is known for being much like humans but in a more simplistic form. Whether or not they are genetically related to humans or not, monkeys truly are very physically similar. Thus, we often see ourselves in monkeys. To dream that you see a dead monkey this means that you feel like that sense of wildness and unpredictability within yourself has died.