Those big eyes scream nocturnal, but the racer-like behavior screams diurnal. Looks wiry and strong as all hell. I eliminated common stuff (black milk, indigo) right away, but if i play much longer, I will have to cheat and pull out reference books. That is no fun, so I give up for the night. Hopefully someone smarter than me (which includes damn near everyone) will have the answer for me by morning. I am running out of colubrids. It is a colubrid, right? I am guessing maybe rear-fanged? I am very confident that it is not a hognose!