Lyrics:

P is for pirate
That's good enough for me
P is for pirate
That's good enough for me
P is for pirate
That's good enough for me
Pirate Pirate Pirate starts with P

A pirate with one leg looks a bit like the letter P
A ninja with one leg looks a bit like the letter P
But that is not as good as a pirate
Applejuice looks a bit like P,
but you cannot drink that!

So...

P is for pirate
That's good enough for me
P is for pirate
That's good enough for me
P is for pirate
That's good enough for me
Pirate Pirate Pirate starts with P