"Monthly Feast"
Even just the leaf of a mutant plant could fetch for a high price!
After all, compared to beasts and monsters, mutant plants were rarer, especially those with medicinal attributes that were precious for alchemists and doctors all over the world.
The surrounding animals thought that since the water lily moved, it should be 'that time' of the month where they could get more food than usual.
Although what they would eat was different from their usual diet, it didn't stop these greedy monsters and beasts from eating visitors who came to the lake.
Those near the shore could still attack forest animals every single day, but those living far from the shore had to compete with each other, preying upon each other and so on.
Thus, the 'monthly feast' was important. Even if not every month would yield a good result, every time there was a 'feast', even the small monsters and beasts could get some food residue.