When you enter the sewer, swim left to the first red control wheel, and turn it to lower the water level. Swim back to the right and turn the next wheel, which brings the water to the correct level. Swim left, under the divider, to reach the control room entrance.
(There are two wheels as the water is going down - if you miss the first one, go farther right to find another one that raises the water.)
Ratman is hiding in the sewer under City Park, with his pet rats and stinging flies.
There is a sewer in Early Poptropica, below Main Street, with lots of spiders. The sewer in Super Power Island is under the restrooms in City Park. Go down from inside either one (gender specific).
You can beat the 5 non-flying villains in any order. If you are working left to right, the next is Ratman in the sewer under the restrooms.
There are 5 non-flying villains to beat before you get your super flying power. The only one that is not visible is Ratman, hiding in the sewer under City Park. Go into either restroom and down the hole to reach the sewers.
right under the big maget
it is under the building where the superhero is standing
You can defeat the 5 villains in any order. Copycat and Speeding Spike are Downtown, so the next villains are Sir Rebral in City Park and Ratman in the sewer under the restrooms.
Ratman is in the sewer control room, under City Park. Enter the restroom at City Park, and go down the drain. When you reach the sewer, swim left to the red control wheel. Turning it lowers the water level. There will be other wheels to the right that raise it again, so that you can swim under the wall to the upper left and reach the Sewer Room door. (see the related question)
Go left and lower the water level with the red wheel. Then raise it again until you can reach the door at the upper left (do NOT turn the wheel there!). Go through the door to find Ratman.
The sewer is under City Park, and you can get there by going through one of the public restrooms. Ratman is hiding there with his rats and stinging flies. (see related question)
The five villains you have to beat are Copycat - in the bank Speeding Spike - in the subway Sir Rebral - in the park Ratman - in the sewer (under the park) Crusher - in the junkyard You can play them in any order. Each one you beat will appear on your ID card.
The door is at the upper left in the main sewer chamber, and you cannot reach it. Use the red control wheel at the left side to lower the water level. Then use the other two red wheels (far right, middle right) to raise it again, to where you can swim under the barrier and reach the stairs.