I decided to add this theory
They were soldiers in World War II and were reincarnated as penguins[]
Yes, the penguins were soldiers in WWII. Sadly, they died in the middle of the battle and were reincarnated as penguins. This explains why their names are Skipper, Kowalski, Rico, and Private, they all sound like code names.
Kowalski knows a lot of things that humans have never taught animals[]
He can create weapons, machines and equipment tools. How does he have all this knowledge? Nobody taught him or anything.