Sirius Black's motorcycle

Sirius Black's motorcycle is an ordinary-looking motorbike with a sidecar, though it was huge and emitted a very loud roar. It was large enough to accommodate Hagrid, a Half-Giant half-giant, and still be able to carry an ordinary-size person in the sidecar, and could go fast enough to compete in speed with a broomstick.

The motorcycle belonged to Sirius Black, but it was lent to Rubeus Hagrid shortly after Voldemort attacked and killed James and Lily Potter and attacked Harry Potter, saying he wouldn't need it anymore. At first, Hagrid found this to be very odd, and for a while suspected it had something to do with Sirius' betrayal of the Potters.

Hagrid used the motorcycle to retrieve Harry from the Potter House and bring him to the Dursley House, where Albus Dumbledore and Minerva McGonagall were waiting.

Six years later, when Alastor Moody led a group of members of the Order of the Phoenix to Harry Potter from the house of his relatives shortly before his seventeenth birthday, Hagrid was chosen to drive Harry and his possessions to the home of Ted Tonks. Arthur Weasley had helped Hagrid modify the bike with various buttons that could shoot out magically-produced traps in case of a chase. This turned out to be useful, as Hagrid used buttons to produce a large net, a solid brick wall, and dragon's fire to deter Death Eaters. However, during the chase the motorcycle took major damage, made worse when Hagrid tried to use Reparo to fix it, breaking it more. Hagrid had to dive off the motorcycle to keep them from taking Harry, and ultimately they arrived at the Tonks House, though the motorcycle was heavily damaged. Mr. Weasley hid the bike in his backyard shed in hopes of fixing it afterward.