I have a special fondness for this creature. As it happens, back in the winter of 1988, when I bought the red D&D box, I ran the scenario from the DM book, the one that takes place in Castle Gygar. It turned out the carrion crawler was the first creature the group faced when approaching the castle. Invariably, the creature killed every group in combat since the odds of it striking at least once with one of its eight attacks and the victim failing a saving throw are quite high. I don't remember how I ran the combat or if I was doing it wrong, but the players kept rolling characters and kept bumping into that carrion crawler from hell and kept dying.
I even inflicted the same deaths on a second group I managed to recruit during the following summer vacations. It was the same story all over again: roll characters, approach the castle, fight creature, and die. Rinse and repeat. After a while, nobody ever tried to create fully realized characters. They first wanted to see if they could survive the damn creature before investing on their personas. Amusingly, nobody ever considered avoiding the creature and go straight to the castle. We were young and still learning the game.
As a DM, I was bad. In my defense, I was learning the game, too. I had no one to teach it to me not even other players. This was Portugal in the 80s when roleplaying games were a thing almost unheard of. I get the feeling that it was much the same situation for a bunch of people, 15 years earlier when trying to learn how to play D&D. My only contact in the weeks I was reading the game were a group of players playing demos of the game in a local store, and they were as bad as I was.
Ironically, when I returned to D&D a few of months back, I used the red box again, though I switch to the Moldvay version a session later. And the players also faced the carrion crawler in its hole but this time, they managed to kill it. Today, I am a much better DM as my players are better players, although these are not the same players I started playing with 24 years ago. The carrion crawler will always stick in my mind as an initiation ritual of sorts for my players. Hopefully, the next time I start a campaign, I'll use a different creature... or maybe not.