If there’s anyone who should be allowed to complain about uses of symbols from their works, it’s George R. R. Martin (GRRM). Specifically, the use of the wrong sigil for House Targaryen in HBO’s “House of the Dragon.”
Here we have the Targaryen house sigil from “Game of Thrones” on the left, and the “House of the Dragon” version on the right. If you look closely, the left has one distinct curl in it’s tail, while the right has two. Likewise, the left side has two legs, but the right has four. This was enough of a difference to make GRRM blog on the matter.

“A couple years on, House of the Dragon decided the heraldry should be consistent with Game of Thrones, but they went with the bad sigil rather than the good one,” GRRM wrote. “That sound you heard was me screaming, ‘no, no, no.’ Those damned extra legs have even wormed their way onto the covers of my books, over my strenuous objections.”
It’s not like the wrong symbol is all over the royal fleet or anything-
Oh.

“Someone got sloppy, I guess. Or someone opened a book on heraldry, and read just enough of it to muck it all up. A little knowledge is a dangerous thing,” he added. “For what it’s worth, the shows got it half right.”
“House of the Dragon” is currently in it’s second season, and is available to stream (along with all 8 seasons of “Game of Thrones“) on MAX.