context: this meme is about the battle of san pedro during the french intervention in mexico. the french saw the mexican defense in a cactus field, decided to leave the horses because of all the thorns, and thought it was just a weird terrain choice. turns out the cacti were actually part of the trap, and the french ended up getting stuck in the prickly mess and torn apart. the ending with the exploding prickly pear is just the meme saying ‘yep, a cactus can be a trap.’