"That’s the spirit!" Theo said encouragingly. "Now, back to business. I’ve taken over compiling our research on Cerberi, and I have to say they don’t have a lot of weaknesses. Killing one is certainly possible, but sneaking past one without hurting it would be really difficult. Especially for first years like us. The one on the third floor is being fed twice daily by house-elves, and like all well-trained Cerberi it won’t take food from strange witches and wizards, so we can’t drug it. It naps intermittently, so there’s no particularly good time to try and sneak past it. Its hide is resistant to magic spells, and if you manage to affect it with any kind of mind-altering spell like a Stunner there’s still two more heads alert and ready to rip your arms off in a spray of blood."