In the Underworld after crossing the river of dead.
the cerberus is a 3 headed dog on mythology island on poptropica
You play a song on a flute that puts Cerberus to sleep.
Play the song one of the Muses gave you on your reed pipe. This will make Cerberus fall asleep and you can get its whiskers.
Question: How do you put Cerberus to sleep in mythology island in Poptropica? Answer: It is pretty simple because all you have to do is get the pipe tune from the muse of music (you can find that inside a really musical looking sort of building) you have to get it because it is really important. You go to where Cerberus is then you play the pipe tune that you learned from the muse of music. you get out your pipe and you play it. That is how you get Cerberus to go to sleep in Poptropica
Use the scroll Zeus gave you to find the Minotaur,Hydra,Sphinx,the pearl at the bottom of the ocean,and the whisker from the Cerberus.
You play him the song you learned earlier on the reed pipe.
You play the tune once.
Play the tune the lady with the reed pipe gave you.
Go into Hades' temple. Fall down the hole . Talk to Charon, the boat driver. Beat the mini game, and yoy're at Cerberus.
Use it to get into the Minotaur's lair as well as to put Cerberus to sleep.
the colors are: blue-green-yellow-blue-red-green.this will put cerberus to sleep so you can get the whisker.
you get a flute from Apollos museum and click the music statue and play it for Cerberus