Is that meant to frighten me? Perhaps it would, were your grandfather capable of ending me. Of course, confined to this shell as I am, such a mistake is easily made.
I am, as some others are, unending, though I am not of them, if you take my meaning. I can be, at best, put to sleep and at worst - and this is far more likely - annoyed by the attempt. In the sunken city of R'lyeh have I lain for countless millenia, asleep and awake, not truly dead but dreaming. Civilizations have risen and fallen in what is to me the blink of an eye. All have quaked at the mere mention of a shadow of my name.
I am Cthulhu, granddaughter of Death, and while I may respect your grandfather I do not fear him. Nor do I wish to harm him or his. Know this, however: I do not tolerate threats, thinly veiled or not. For some, I may make exceptions, but only rarely.