Hello the title explain it all, do you know any novels in the dungeons and dragons multiverse with a dragon a s the main character ??

these are just forgotten realms:

• Death of the Dragon, by Ed Greenwood and Troy Denning (hardcover, August 2000, ISBN 978-0-7869-1637-5; paperback, May 2001, ISBN 978-0-7869-1863-8)

also the Year of Rogue Dragons trilogy:

• The Rage, by Richard Lee Byers (paperback, April 2004, ISBN 978-0-7869-3187-3)

• The Rite, by Richard Lee Byers (paperback, January 2005, ISBN 978-0-7869-3581-9)

• The Ruin, by Richard Lee Byers (paperback, May 2006, ISBN 978-0-7869-4003-5)

• Realms of the Dragons, edited by Philip Athans (paperback, October 2004, ISBN 978-0-7869-3394-5)

• Realms of the Dragons II, edited by Philip Athans (paperback, May 2005, ISBN 978-0-7869-3808-7)

(the last two are a series of short stories taking place around the time of the first 3)

one of the waterdeep books also has a dragon as a main character, can't remember the name though.

Main character is a bit of a stretch but second and third book of the Dragonlance Chronicles. (Read all three though they are great). 

and do you know others with dragons as main characters outside the DND multiverse, in another fantasy setting ?  (i rode every books of eragon and E.E knights' books)

There’s an old Choose Your Own Adventure called Ring of the Ruby Dragon, but it costs like $30 on eBay.

Gleep from Myth Adventures is the real hero like R2D2.