Probably the coral snake. Beautiful little snakes, and venomous as fuck. Despite the potency of their venom, their bites are rarely deadly. They're rear fanged, and don't typically inject much venom if they bite a person. They have better things to do with that deadly fluid. They're also relatively docile compared to most venomous snakes.

My first favorite reptile is the rubber boa. They're so chill that you can find one in the forest, wrap it around your wrist, and it'll stay there like a bracelet all day long. If it's a tiny one then you can wear it like a thumb ring. They appreciate the warmth and are happy to just chill on your arm. When you're done wearing snake jewelry, you just put them back where you found them, and they'll go on with their little snake lives, having experienced something unbelievable, which they will likely remember with fondness forever.