Horror story fan scared by kitten in red & white striped sock?

This cartoon has stuck, vaguely, in my memory since early childhood. I caught it on local Boston-area TV in the early 1970s, and only saw it once or twice. Basically, it's about man who is a voracious reader of horror stories, absolutely obsessed with them. I'm not sure, but I think he's portrayed as jaded... he enjoys the lurid tales, but they don't particularly scare him (either that, or he's addicted to horror stories, so needs scarier and scarier stuff to feed his habit). He lives in either an old house or a small apartment (my recollection is shaky on that point)... his bedroom has a brass bed, surrounded by stacks of horror-themed books and/or horror comics.

Anyway, at the climax of the cartoon (which is what I remember most), a red & white striped sock crawls up onto the foot of his bed, looking like a creepy alien worm. I think it may match the description of the monster/creature in the book he's currently reading, so it scares the living daylights out of him, crawling closer and closer. He's paralyzed with fear. Suddenly, it's revealed to be a kitten, that crawls out of the sock and relieves his terror/wins him over. It seemed to be mainly concerned with telling a story (and probably a moral of not getting too caught up in horror stories); I don't recall it having any traditional cartoon gags in it, though I could be wrong. I also believe the cartoon had a narrator, who was either the main or only voice heard, throughout.

When I saw this, I was barely more than a toddler, and our TV was a black & white model. Racking my brains, and knowing what I know about cartoons/animation today, I'd guess that the short was probably made sometime between the early 1950s and early 1960s, and I'm pretty sure it was made in color, even though I wouldn't have seen it that way on our TV. The plot, style and tone was the sort of thing that could've easily been one of UPA's one-shots, but I've seen them all (and own the DVD collection), so I know that it isn't a 'Jolly Frolics' short. I suppose it could've been a Paramount Noveltoon or Modern Madcap... or perhaps a latter-day Terrytoon, but I'm doubtful. Perhaps it was made-for-TV, but it seemed to be more like a theatrical, in the haze of memory.

I have a nagging suspicion it was of European origin, likely either Czech (Zagreb studios?) or French. I'm pretty sure it was part of a specific package of such cartoons, as I remember another one, around the same time (probably in the same syndication package) about a mouse trying to sneak past a cat by disguising himself with the bloom of a flower, the cartoon built around Tchaikovsky's 'Waltz of the Flowers'. YouTube and Google searches have been fruitless, so far, but I'm probably missing a vital keyword or two.

A few years ago, I was talking to a friend of mine in the animation industry, and he remembered both cartoons (he may have even had old prints in storage), but he somehow neglected to tell me who made them or their specific point of origin, or maybe such details slipped his mind at the time.

So, does this cartoon sound familiar to anyone?

Wow, thanks, that's definitely it! Another mystery finally put to rest... and it's interesting to see what my foggy memory got right and got wrong, after over 40 years! Much appreciated!