Mean Greenie was already on his last days when he started sitting upright at the bottom of his bowl and could no longer eat the pellet food with the great accuracy he had when he was healthy.
The pH levels and the hunger eventually did him in. He probably only stayed around a little while longer to cherish the last moments of watching Mighty Aphrodite swimming around in her bowl nearby.
He was the first green betta of the bunch and one of the biggest and strongest among them. The only betta in the Betta Babies™ that will have currently outlived Mean Greenie is Anthem.