Flip and Pate's Magical Potion Adventure by Lori Rousche

Sophia MacAllister Phlippet, "Flip" to her friends and family, is a fifth-grade witch who is tired of getting picked on by her nemesis, Justin Johnston. With help from her best friend, Pate, Flip intends to put Justin in his place with a magical elixir she creates using her family's potion bible. Justdumb, as she refers to him, also has the unusual gift of dabbling—or making magic potions—unbeknownst to Flip. Both come up with tricky ways to get the other to drink the mixtures. The Brookdale Elementary School becomes a crazy battleground of screaming, nonstop burping, werewolves, and dogs. Pate tries to make peace between Flip and Justin and gets caught in the skirmish. Flip never thought she would have to choose between winning the potion war and keeping a friend.