Sounds like a snake. :)

The only thing I would check is whether there is a temp spike (2-5pm is the hottest part of the day in AZ, our temperatures are no joke, which is what makes me think of it) during that time which makes him feel like getting out of his hide. Otherwise, I guess you just have a very afternoon-active animal. It's pretty normal for them to "climb" the walls. As long as his husbandry is on point, you're just catching a glimpse of his unique personality.