From Creatures Wikia
The Trapper's gaping mouth and teeth may look suspicious, but it is not at all dangerous to Norns - indeed, it is a greatly beneficial plant! A multitude of trappers can be a great help in clearing up a rampant Stinger infestation. Once they have eaten enough Stingers, they will spread several seeds and then die. If you want more of them in your world, the Trapper Planter might help.