Oxyrhopus vanidicus — Mimic False Coral Snake
This species was split from Oxyrhopus melanogenys by John D. Lynch in 2009, based on the shapes and pattern of the dark bands near the snake's neck. However, this seems like a pretty iffy distinction, so I won't argue with you if you consider this to be O. melanogenys.
Santa Cruz Forest Reserve, Loreto, Peru—January 20, 2014
Mimic False Coral Snake (Oxyrhopus vanidicus)
I found this snake stretched out on the grass between the Santa Cruz facility's main building and bathroom building. I tried to get a photo of it there, but it decided to head back towards the forest rapidly, so I grabbed it and got a few posed photos the next day.

Here is a complete list of the herps I saw in the wild on my 2014 MT Amazon Expeditions trip.

Santa Cruz Forest Reserve, Loreto, Peru—January 31, 2022
Mimic False Coral Snake (Oxyrhopus vanidicus)
We found this large Oxyrhopus vanidicus in the forest at the end of a long night, almost all the way back to the field station. It had no interest in posing for us in the forest and we were tired and impatient so we brought it back for daytime photos the next day (before releasing it back where we found it, of course). It didn't really have much interest in posing for us during the day either.
Online references: