SpellsCurse
Furnunculus
A jinx that causes boils. Harry's spell strikes Goyle during an exchange with Draco in Goblet of Fire. Later Harry uses it on Crabbe, where it combines badly with George's Jelly-Legs Jinx.
In the books
Harry Potter and the Goblet of FireChapter: 18
Harry’s spell rebounds during a clash with Draco and covers Goyle’s face in boils.