The wounds on Hellboy's chest disappear when he rips open Hecate's "iron maiden", then reappear.
The goddess Hecate can be pronounced either 'heck-a-tee' or 'heck-ate'. The latter is used here. It probably originated among actors performing William Shakespeare plays (which often listed the Roman deities), when they saw the word in print and used their own judgment when speaking it. These mispronunciations then became standard Shakespearean theater convention, and have crossed from pop culture to the common language whenever ancient figures are discussed. Honored Shakespearean performers continue to pronounce Jacques and Marseilles as "Jakies" and "Marsellus" in the context of the play, and use the "ay" sound (rather than the classical "ah") for the a's in Cleopatra and Coriolanus, the latter being especially giggle-worthy.
In 1610, Erzsébet's favorite "toy" is an Iron Maiden. This instrument of torture was invented in 1793 for display in carnivals.