Although their mother wanted the twins to work for the Ministry of Magic like their father, the twins' ambition was to open a joke shop to sell their inventions. With Harry's seed money, the twins did just that, first testing their product ideas, then launching an mail-order business "Weasley's Wizard Wheezes," during their last year at Hogwarts. After they quit school they opened a very successful shop at 93 Diagon Alley. With the 1996 closure of Zonko's in Hogsmeade, the twins now appear to have a monopoly on the magical joke and gag industry, in fact the twins told Harry were considering buying the Zonko's shop.

Inventions:

* Fake wands
* Weasleys' Wild-Fire Whiz-Bangs
* Canary Creams
* Extendable Ears
* Skiving Snackboxes
* Headless Hat
* Nosebleed Nougat
* Portable Swamp
* Puking Pastilles
* Ton-Tongue Toffees
* Punching telescope

For sale at Weasleys' Wizard Wheezes:

* Skiving Snackboxes (Nosebleed Nougat is the most popular)
* bins full of trick wands
* boxes of quills (Self-Inking, Spell-Checking and Smart-Answer)
* Reusable hangman
* Patented Daydream Charms
* Muggle card and rope tricks
* Edible Dark Marks
* Shield Charms (hats, cloaks, gloves)
* Instant Darkness Powder (imported from Peru)
* Decoy Detonators
* Joke cauldrons
* "WonderWitch" products (love potions, Guaranteed ten-second pimple vanisher)
* Pygmy Puffs (miniature puffskeins)

Other devices: Filibuster’s Fabulous No-Heat, Wet-Start Fireworks, Cleansweep Five broomsticks, Stink Pellets from Zonko's, Marauder's Map ("the secret of our success"), Dungbombs.

Substances, restricted and otherwise: Venomous Tentacula seeds, Bulbadox powder.