Clue's in the Monkey Drool is an achievement that requires the player to receive the medium clue scroll from the monkey in the player's inventory during or after the Monkey Madness quest, after feeding it a number of bananas. The drop rate is 1 in 256.
It is recommended to buy bananas off the Grand Exchange and feed the monkey at a bank. This will display the message "The monkey chews on the banana and spits out a clue!" in the chatbox. To obtain the clue scroll the player must not have reached the cap of 25 sealed and active combined medium difficulty clue scrolls in their inventory nor bank; however, another difficulty clue scroll won't interfere. Do not skip the dialogue when feeding the monkey, as it will not count as an attempt towards the clue scroll.
Prior to the Clue Scroll Overhaul on 26 February 2018, players could not have a medium clue scroll in their inventory nor bank and receive a second clue from the monkey.