He's Charizard, the Charizard. He is a Charizard and belongs to  djlwna, thus, Lwna's Charizard, the Charizard.
He has a Google Translated story about him and how they are now BBFs and how he got those scars and stuff.

You can check his gallery where this and other two illustrations are, along with the story.

The Line art was done by me 3 a few years ago, the coloring was done by someone who wants to remain anonymous for some reason.

And he basically belongs to and the Pokémon Company. And Nintendo. And Satoshi Tajiri. And Red.
And Ash. And Alain.