https://www.youtube.com/watch?v=GMtlp6TA3zA
random encounter - 60% chance - 5 bulette https://roll20.net/compendium/dnd5e/Bulette#content
non combat event - out in the distance, one person on watch sees flashes of light. upon moving closer, they'll see corpse flower(s) eating a badly beaten (dead) man (former wizard). If there is nearly everyone, there's two flowers, each eating half of him. If there's 5 or less, there's only 1 they can fight them if they want, but it'll take everyone.
random encounter - 60% chance - 3 Treants https://www.dndbeyond.com/monsters/treant