YOU SAID:

Piper is a penguin I am friends with.

INTO JAPANESE

パイパーは私が友達なペンギンです。

BACK INTO ENGLISH

Piper is a penguin I'm a friend of.

INTO JAPANESE

パイパーは私が友達のペンギンです。

BACK INTO ENGLISH

Piper is my friend Penguin.

INTO JAPANESE

パイパーは私の友人ペンギンです。

BACK INTO ENGLISH

Piper is my friend Penguin.