well it's simple! just use the song sheet that statue with the reed pipe gave you and play it on your reed pipe, the Cerberus will then fall asleep and when you walk across it's body, you'll get the whisker. When i did this, i went back to the grove and Zeus commits the biggest crime ever!
first play music to put it to sleep, then click on its heads
you play to it on a lute with a song from the temple.
How to get cerberouses whisker is play him the song the muse tought you. (Find the muse where you got the reed pipe from Apollo). ;)
You blow tune on reed pipe
you go the the dog and click on it so you can get its whisker
first make him fall asleep then click on him
You play him the song you learned earlier on the reed pipe.
you play it a song fom the music temple on a reed pipe
speak to the inspiring statue with the flute. She will give you a tune to play to the dog.
You go to Hades realm and open the door by placing the pomegranates on it. You go down to the river styx and make it all the way. Then you will get dropped off on the other side of the river facing a three-headed dog (Cebrus). You play the tune on the pipe, which you can get in Apollos temple, and the dog falls asleep. Then you can take the whisker of of the dog.
You use the reed pipe and these are the the notes you play: blue, green, yellow, blue, red, green. And then he will fall alsleep and then click on his mouth and you got the whisker!
In Poptropica, to obtain the whisker from the Underworld in the “Mythology Island” quest, you need to navigate through the Underworld and interact with the various characters. You must help Hades by retrieving a special item or completing a task he requests. Once you do this, Hades will reward you with the whisker. Make sure to explore thoroughly and interact with all available items and characters to progress effectively.