right beside the cafe place.
The mayor of the town on 24 Carrot Island will give you the Island Medallion when you complete the quest.
He is at the carrot factory.
He is the first (and last) person you talk to on the island. He is wearing a top hat at the entrance to the island. When you have beaten the evil Dr. Hare, the mayor gives you the Island Medallion.
Follow the freed worker up the rope to the outside and get your medallion from the mayor.
on the factory window
When you finish the mission, go to the mayor and he'll give you the medallion. He has a black hat.
Crash the space rabbot into meteors and destroy it. Then follow the kid out on the rope or use the Carrot transporter to exit the factory. See the mayor and get your Island Medallion.
You can talk to the mayor, then go to the diner to learn about the missing kids. The first step is to find the cat for the clerk at Charlie's Carrot Surplus. This will gain a necessary item. (see related question)
fight
Ratman is on Super Power Island. There is a large rat in the sewer entrance to the factory on 24 Carrot Island (climb up into the bypass pipe to elude him).
it is on the 24 carrot island on the gas station
24 Carrot Island is the 4th island of Poptropica. It came out in June, 2008.