I forgot the name of an anime I used to watch as a kid =(?

It is a pretty old anime.

I remember it was about a kid who was raised on a island with monsters.

He had a yellow flying creature friend with him.

I remember the mentor gave up his life to save him and his apprentice.

Then they started a journey together.

The female who joined the group later had a magic gun that was given to her by the dead mentor.

If you know the anime's name or if you could find out what it was I would really appreciate it. Thanks.