Yes, some cacti are psychoactive. The most well-known psychoactive cactus is probably the peyote cactus (Lophophora williamsii), which contains the alkaloid mescaline. Mescaline produces psychedelic effects similar to those of LSD or psilocybin mushrooms. Other psychoactive cacti include the Peruvian torch cactus (Echinopsis peruviana), the San Pedro cactus (Trichocereus pachanoi), and the dragon fruit cactus (Selenicereus megalanthus). These cacti contain various alkaloids that can produce psychedelic effects, including visual hallucinations. So if you're looking to trip out on some cactus, there are definitely options available. Just be sure to do your research beforehand, as some of these plants can be quite potent. And as always, start with a small dose to see how you react.