The homeless bird has been seen alive after many were worried it wouldn't be able to survive in the Tokyo city waters.
The penguin, only known by the number 337, is likely surviving on small fish during the day and returning to shore to rest at night.
To escape, 337 climbed up a rock wall 13 feet (4m) high and managed to get through a barbed wire fence.
According to Reuters, the deputy director of the aquarium said: "It didn't look like it has gotten thinner over the past two months, or been without food.
"It doesn't seem to be any weaker. So it looks as if it's been living quite happily in the middle of Tokyo Bay."
The director believes that 337 escaped due to its sense of adventure.
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