The story concerns a team of archaeologists investigating Mayan ruins who come across a deadly creature that is a shapeless amorphous blob. They manage to defeat it using fire while keeping a surviving sample of the creature which, ultimately, leads to more death and destruction when the archaeologists return to Mexico City.
You can read more about Caltiki through this well-written review from the blog-site Cool Ass Cinema.
Here's the trailer to wet your gooey appetites:
Alternative upload of the trailer, just in case:
Here's the feature-length film itself:
An alternate upload of the same film because, again, we're dealing with YouTube here:
If you enjoyed the film than I'd recommend the recent Blu-ray release from Arrow Video which, as you'll see in this ad, is teaming with bonus features:
And, lastly, a humorous second opinion from Dark Corners Reviews: