I've been scouring the Internet the last few days. I am at a loss, I can't find anything on this. Years ago I woke up in the middle of the night and caught some rerun of an old black and white show on TV, I can't remember the channel, the name of the show, or even the episode. More on the title at the end.
It was a horror/mystery type of anthology show, similar to Twilight Zone. The episode took place in this family's house. I think there was a storm outside? Possibly a snowstorm. I think the parents were warning the kids not to go outside or open the doors or anything, otherwise 'it' will get you. I'm pretty sure they called it... 'the grizzle' or the 'gribbel' or something along those lines. One word, pretty sure it started with G, maybe D. At the end of the episode the monster showed up and I'm pretty sure it actually got the family. The name of the episode was the same as the monster, so it was 'The [BLANK]'. The monster looked like the abominable snowman, almost, except it was much, much, much larger. I think its arm basically reached through an entire door at the end.
I am struggling so hard to find this, I know I watched it. It was very creepy given the entire episode took place basically in the living room. Black and white, had to be in the 50s, I've searched through every episode on Wikipedia of shows like The Outer Limits, Alfred Hitchcock Presents etc. and I cannot find it, I have no ideas left now.