Monkey dreams symbolize cleverness and trickery. A monkey performing tricks means using wit and wisdom to overcome difficulties. Having something stolen by a monkey warns of a crafty person around you. A laughing monkey hints at joyful events or gaining popularity through humor.
Animals appearing in dreams — as in "Monkey Dream" — often symbolize instinct or a suppressed impulse in Jung's theory of Archetypes. The specific animal and the emotion it evokes in you both shape the meaning far more than a generic dream dictionary entry can.
What was the first emotion you felt when you saw that animal in the dream?