My absolute favorite Orca culture story (yes they have transmissible culture!) is the “salmon hat craze,” where the Orcas carry dead salmon around on their heads, apparently just for fun: https://en.wikipedia.org/wiki/Salmon_hat

When you’re the apex predator of the world’s oceans you can get away with all sorts of silly nonsense!

Killer Whales, aka Orcas, actually are dolphins!

And they got their name as a mistranslation into English - if I remember correctly they were originally named in Spanish as "killers of whales" or "whale killers", because they do that

> if I remember correctly they were originally named in Spanish as "killers of whales" or "whale killers", because they do that

Wiktionary supports that etymology, and it is generally a high-quality source for etymology, but it's troubling that this one isn't cited.

All dolphins are whales. Not all whales are dolphins. It's a square / rectangle situation.

Orcas are indeed dolphins, and also whales.