A great movie for trashing. Watched it under the (illegitimate) title of Anaconda. The monster is never refereed to as pirahanaconda, just giant snake or random mutation, because scientist, in the movie but it's so generic SyFy I landed on the name on my own.
Constant lack of continuity, clearly missing scenes, obvious reshoots (the blond c story actress obviously got plastic surgery between primary and reshoots, so good on her but she literally can't talk for the botox) and the awful opening/closing music sounds like a direct rip of the old Spider-Man theme. If you know bad monster movies you can predict beat for beat the generic character traits and lines.
Location is gorgeous but obviously shot a resort's botanical path and nearby public parks for the most. The practical model is much better than the CGI.
Spoilers EVERYONE DIES so A+ for that.
Watch with your favorite legal mind altering substance and a friend or four.