Aztec/Mayan Temple Guardian monster, puzzle, and encounter ideas? [closed]

In a few weeks, I’m running a 10th level DnD 5e Indiana Jones-esque one-shot type jungle adventure in my homebrew world. My players are fighting golems, dinosaurs, etc. But I’m struggling to design a cool and engaging encounter when they finally reach the top of the ruined pyramid they’re going to explore. The pyramid was built by sun-worshipping natives that had a strange connection with extraplanar and alien beings. What kind of monsters do you think would be interesting and cool to be guarding this place at the top of the pyramid? I’m also planning to make this puzzle were they have to figure out a way to open a circular pressure plate at the center of the chamber at the top of the pyramid to enter as well, and would like to hear your suggestions or ideas on how I could execute this?

I’m open to all suggestions!