Dragonslayers by Bruce Coville

[Aladdin] A brave squire, an earnest page, and a strong-willed princess set out on their own missions to slay the dragon—putting a fresh twist on classic tropes—in this repackaged edition of the illustrated middle grade fantasy The Dragonslayers. When the witch Grizelda decides to get revenge on King Mildred, she doesn’t go halfway. She makes the fiercest dragon the kingdom has ever seen. Now the kingdom is in dire need of a dragonslayer. With most knights reluctant to face the fire-breathing beast, the king decides to add an incentive: whoever slays the dragon will get half his kingdom and will marry his daughter, the princess Wilhelmina (a.k.a. Willie). Two unlikely candidates take up the challenge: the squire Elizar and the young page Brian. Willie, however, has no intentions of marrying anyone, so she sets off to face the dragon herself. The quest soon becomes a race. Who will find the dragon first, and will they survive the encounter?