I agree it looks like the umbilical scar, no cause for concern. They do become more aggressive as they grow & do indeed become waste disposals. I have 5 different Dry`s species & they all eat with gusto, although as neonates they are nervous & shy but this nervousness turns into boldness. They also have an intelligence & personality not seen in most snakes. Try to give them variety, mine take the following items.

Rodents, chicks, quail, fish, skinless chicken necks, roadkill snakes etc.

Enjoy,

Andy.