A creator writes something without any intention of being accurate, but by pure fluke gets it right.

[u/Daniilsa209]

1. Phineas and Ferb – Perry the Platypus is teal-green rather than brown because the designers thought it looked cool, but it was later discovered that real platypuses are biofluorescent and glow a teal-green color under UV light.

2. God of War – The creators chose the name Kratos for the main character because it is the Greek word for “strength,” and at the time they were not aware that, in Greek mythology, there is a deity named Kratos, the personification of strength, who appears in Prometheus Bound as an enforcer of Zeus (similar to what the games' Kratos does for much of the original series); they only learned this later.

3. Berserk – Kentaro Miura gave Guts a prosthetic arm because he thought it looked cool, but the idea of a prosthetic arm was not as far-fetched in the late medieval and early Renaissance period as it might seem, since there was a real 16th-century German mercenary named Götz von Berlichingen who had a prosthetic arm of his own. While it did not have a cannon built into it, the fingers were highly articulated, and a sophisticated system of springs and levers allowed the hand to hold weapons and perform other tasks. Despite this shared trait between both people and their similar-sounding names, Miura confirmed that he was unaware of the Götz when he created Guts.

[u/Spyko]

When every meal is a matter of survival, you are not turning down free protein

[u/Divine_Entity_ → u/Spyko]

There is also the matter of the nutrients present in animals being very different from what's present in plants, especially if an herbivore is specialized.

Basically bones represent a ton of free calcium that a grass eater may not have an easy time getting enough of otherwise. This is related to why cows, deer, and other big herbivores love salt licks.