Colorado River Toad (Incilius alvarius) and Rio Fuerte Beaded Lizard (Heloderma horridum exasperatum)

What is the other animal in the photo?

It was not signed but it looked a bit like a Mangrove monitor.

I believe it's not a monitor lizard, but rather a Beaded lizard, due to the head shape and overall format of the body and tail. Judging by the patterns and colors of the animal, I would say it is a Heloderma horridum charlesbogerti, aka the Guatemalan beaded lizard.

I checked my notes (which I should have done first) and it is indeed a beaded lizard.Thx

You're welcome!