An incorrigible prankster, the Saci will not cause major harm, but there is no little harm that he won't do. He will hide children's toys, set farm animals loose, tease dogs, and curse chicken eggs preventing them from hatching. In the kitchen, the Saci would spill all salt, sour the milk, burn the bean stew, and drop flies into the soup. If a popcorn kernel fails to pop, it is because the Saci cursed it. Given half a chance, he will dull the seamstress's needles, hide her thimbles, and tangle her sewing threads. If he sees a nail lying on the ground, he will turn it with the point up. In short, anything that goes wrong — in the house, or outside it — may be blamed on the Saci.
Besides disappearing or becoming invisible (often with only his red cap and the red glow of his pipe still showing), the Saci can transform himself into a Matitaperê or Matita Pereira, an elusive bird whose melancholic song seems to come from nowhere. One can escape a pursuing Saci by crossing a waterstream: the Saci will not dare to cross, for then he will lose all his powers. Another way is to drop ropes full of knots; the Saci will then be compelled to stop and undo the knots. One can also try to appease him by leaving behind some cachaça, or some tobacco for his pipe.
Every dust devil, says the legend, is caused by the spin-dance of an invisible Saci. One can capture him by throwing into the dust devil a rosary made of separately blessed prayer beads, or by pouncing on it with a sieve. With care, the captured Saci can be coaxed to enter a dark glass bottle, where he can be imprisoned by a cork with a cross marked on it. He can also be enslaved by stealing his cap, which is the source of his power. However, depending on the treatment he gets from his master, an enslaved Saci who regains his freedom may become either a trustworthy guardian and friend, or a devious and terrible enemy.
In order not to let this folklore die, the city of Botucatu, in the state of São Paulo, holds a Festival in the month of October to pay hommage to this prankster. Some city dwellers claim to raise some of them, and sacis are allegedly seen in the woods close to the city.