That's definitely one of my favorites.
I also like this one just for the insanity lol
https://esolangs.org/wiki/5D_5D_Brainfuck_With_Multiverse_Ti...
Quick description:
Like 5D Brainfuck With Multiverse Time Travel, 5D 5D Brainfuck With Multiverse Time Travel With Multiverse Time Travel operates on an array of 5D Brainfuck With Multiverse Time Travel program cells initialized to the 5D 5D Brainfuck With Multiverse Time Travel With Multiverse Time Travel program's source code (treated as a 5D Brainfuck With Multiverse Time Travel program). Multiple pointers to memory, and to the program, may coexist in each timeline. The state of the tape is stored as a timeline, allowing programs to rewind time. In addition, programs may create and traverse parallel universes, which are timelines that all execute simultaneously, "below" their parent timeline. Each timeline has its own pointer.
The wiki page for "5D Brainfuck with Multiverse Time Travel" claims that `(-^.[.]),[,]` is "cat, but faster." But it seems to me that the `.` would never print anything, because the lower universe contains no memory pointers at that point — the only one traveled to the upper universe as a result of the preceding `^` instruction (so now the upper universe contains two memory pointers). Am I missing something or does that example not really work as advertised?
I have no idea. Never tried it. I just love the description to send to people lol