The Engorgement Charm
A growing charm that could be used to swell and lengthen items. If used carelessly the spell could cause the target to swell to such a size that it exploded. Usually learned alongside its counter spell - the Shrinking Charm - one could not be safely used without the other to hand. Hermione suspected that Hagrid (with the help of his illegally concealed wand) used the spell to help grow his pumpkins, whilst Fred and George's Ton-Tongue Toffees also carry the charm.
