Drugs in your drink
This is a common scam in Brazil and even happened to famous Brazilian celebrities. You go to a bar and you make a friend there or outside and he might buy you a drink. This drink can have a drug that will make you like a zombie. You will be able to walk and answer questions but you will not be able to understand what's going on or remember anything the next day. Usually, the scammer will take your money and credit card or ask you to withdraw money and you will do it. Always make sure you don't allow anyone that you don't trust to handle your drink.