The famous venomous spider I believe you are referring to is the Brazilian wandering spider (scientifically known as Phoneutria). It is highly venomous and is considered one of the most dangerous spiders in the world. The Brazilian wandering spider is known for its aggressive behavior, potent venom, and its habit of wandering on the ground at night, hence its name. It is found in South and Central America and is notorious for its venomous bite, which can cause severe symptoms and even be lethal if left untreated.