If you’re quite familiar with the symbol below, it could be the Deathly Hallows symbol from Harry Potter. If you know that, then I’m assuming you also know that a deer has so much value for a couple of characters in the story.
The Non Slip Loop Knot. The strongest loop knot you can tie. Used by big game anglers worldwide. Easy to tie, far stronger and more reliable than the old fashioned strangulating figure eight knot that can substantially weaken line.