Once you have the password from the Printing room, have gone to the Processing room for the wire cutters, cut the wires in the Freezer room and return to the Processing room again. Dr. Hare is in the Launch Room to the right. Free the two drones and press the door marked "Drones Only". Down in the Preparing Room, you will find a pair of rabbot ears to use at the door. Go in and pretend to be under Dr. Hare's control.
Dr. Hare
24 Carrot Island does not have a cockpit. 24 Carrot Island was released in 2008 and the main objective of the game is to stop the evil Dr. Hare from controlling Poptropica.
That is not part of the 24 Carrot Island quest.
The "carrot blender" on 24 Carrot Island is a factory machine that formerly created ingredients for carrot cake. It has been altered by Dr. Hare to make rocket fuel.
If you've finished the island, clearly you've destroyed him. You cannot find him if you've finished the island.
Follow the kid when he climbs up the rope, and you will find yourself back on Main Street. Or you can use the Carrot Transporter and walk back from the factory.
He is at the carrot factory.
Go to the air balloon and do another quest on a different island.
There is no cockpit on 24 Carrot Island. When you enter the Launch Room, Dr. Hare enters the control room of the Giant Space Rabbot and you launch it into space. (see related question)
There is no Hop Island. There is a giant space rabbot and an evil pink hare on 24 Carrot Island. (see related question)
The only underground apparatus on 24 Carrot Island is the equipment stealing the carrots from the carrot farms. (They are used to make rocket fuel.) The operations of the evil Dr. Hare are all in the old Carrot Cake Factory to the far right of the island. You can get in through the sealed waste pipe if you have a crowbar. (see related question)
Dr. Hare is the mastermind of the plot to steal all the island's carrots. He is using them to make rocket fuel for his giant space rabbot. You have to find him and prevent him from succeeding.