Not the best Christmas surprise: one to drive you straight to the mulled wine!
I was interested to learn that this is one of very few venomous Colubrids (Grass Snake family). It was considered harmless for many years, until an American herpetologist died after being bitten; because of the perceived lack of risk, he ignored the bite. (https://snake-facts.weebly.com/boomslang.html)
They have a lot at Stofbergsfontein and i’m told they go after the weaver nests. Lots of stories about snakes from the lagooners. Must double check before I quote