Every Witch and Wizard owns at least one cauldron. This versatile item can be used to brew potions, to carry supplies, and, in a pinch, to clobber an attacker. 

• collapsible and other cauldrons for sale on Diagon Alley (SS5)
• some wizard somewhere along the line invented selfstirring cauldrons, a fact which the First Years had to remember for their History of Magic exam at the end of the year (SS16)
• cauldrons carry a LOT of books, which suggests that they might have enchantments on them (CS
• young Bruno Schmidt of Germany hit an Erkling over the head with his father's collapsible cauldron and killed it (FB).
• Neville melts his sixth cauldron in Potions class
• Percy spends a lot of time writing a report about imported cauldrons with defective, thin bottoms as part of his job at the Ministry of Magic (GF
• Fire-Crab shells, which resemble tortoise shells encrusted with jewels, are prized by unscrupulous Wizards as magical cauldrons (FB)