This mainly stemmed from a conversation with @Whisperlisc and @Blue Moth
What if spiders could hide inside or disguise themselves as cacti?
Spiders could curl up or cover themselves with bits of cactus flesh. Or, they could dig under the cactus and get inside of the plant. So when something would get near the spider or (Tried) to pick the "Cactus" the spider would reveal itself and attack.
This isn't something I would want in the game, it's just an idea.
Fun fact: Some species of spider will sometimes disguise themselves as ants.