Not sure if this is true or in my head, but here’s the 尾 mnemonic:
You see a flag stuck in the ground with a little bit of fur coming out from it and on closer inspection you realize it’s actually a tail. Someone stuck a flag into some sort of animal, pushing it under the ground. All that’s visible now is some fur and part of the tail. What kind of animal could it be? You start to feel the soft fur with your hand and then the stench of death hits your nostrils. Ew. You try to pull the flag out of the ground and hear a rumbling buzzing sound. At the end of the flagpole you see a huge beehive (び)! These bees made their home under the tail! Maybe that’s why the flag was sticking in it… to warn people. Oops. See the bees swarming out from around the tail and toward your face. Run! Run before there’s nothing left of you but your own tail!
And here’s Judges 14:5-8 (KJV):
5 Then went Samson down, and his father and his mother, to Timnath, and came to the vineyards of Timnath: and, behold, a young lion roared against him.
6 And the Spirit of the Lord came mightily upon him, and he rent him as he would have rent a kid, and he had nothing in his hand: but he told not his father or his mother what he had done.
7 And he went down, and talked with the woman; and she pleased Samson well.
8 And after a time he returned to take her, and he turned aside to see the carcase of the lion: and, behold, there was a swarm of bees and honey in the carcase of the lion.
Something about a dead tailed animal infested with bees just reminded me of that story. There are other religious references, such as the 命 mnemonic (which talks about the Book of Enoch) and Jesus being the mnemonic character for じ, so it seems plausible to me.