One of my favorite frogs! Spent some time specifically looking for it. Managed to find two near Cobá, in Quintana Roo (in the Yucatán peninsula). This frog hides in holes in lime stone and tree trunks, and makes use of its flat head to block the entrance. This type of defense is known as phragmosis.
Some other shots:
Oh my god, HIS HEAD IS SO SMALL, I love him 😭