I’d say it’s definitely a Oxychilus draparnaudi, or in the Oxychilus genus! They (Oxychilus draparnaudi) are commonly known as glass snails, but their FULL common name would be “dark bodied glass snails!”
Oxychilus are usually 16 mm diameter and 8 mm in height, so if it’s any bigger than that, it’s likely it’s a different species, yet in the same genus.
Hello again! I am free to help anyone with snails or slug questions! I own a snail rescue and a snail YouTube channel, so I have had lots of experience over the years.
I have way too many snails to count, but here is a few.