early 2000's movie that has a scene where a guy is in a river with possibly a flute and a big hairy creature comes and kills him

In this campy throwback to 1950s monster films, a vicious monster, the Riverbeast, has arisen from its watery lair to terrorize a peaceful New England town. Local tutor Neil Stuart has seen the beast before, but nobody believed his story, making him the town laughingstock. Neil sets out to not only prove that the Riverbeast exists, but also, with the help of his beautiful pupil, scrappy tutor buddies, and a former professional athlete, to vanquish the aquatic menace!

A leisurely, beer-filled vacation for a group of partying students turns into a nightmare. After contracting a whitewater river tour, the kids learn that something is stalking them on the legendary Mogollon Rim. Some people believe it to be the mythical Mogollon Monster, but others aren't so sure. No one is safe, including the staff of the river tours, as a force wreaks havoc, slaughtering anything in its path. No phones. No weapons. No chance. The only thing separating the students from certain death is how fast they can paddle.

Four kayakers take the wrong river into a jungle inhabited by a tribe of merciless cannibals.