My pet peeve: alseids, cecaelia, alacorns, *taurs, and other misused and invented monster names

So a common pet peeve of mine is when Pathfinder bestiaries get etymology and mythology wrong, because this tends to bleed over into discussions of actual mythology and result in tons of misinformation being spread.

Here are a few examples:

• In Greek myth, the alseides are the dryads of groves, who liked pranking travelers. They were not deer-centaurs, that's WarCraft's dryads.
• The cecaelia, an octopus-mermaid, is not a mythological creature. 
• The alacorn, a winged unicorn, is not a mythological creature either. However, the "Ethiopian Pegasus" was a breed of winged horned horse recounted in the natural histories of Pliny.
• The centaurs are self-explanatory, though the term itself is used more freely in Greek myth to refer to more than just the horse/men hybrids. Weirdly, the word taur (literally "bull" in Latin) is used to describes centaurs with non-equine lower halves, even though the word centaur already served that role in Greek myth. E.g. horse-centaur, fish-centaur, bull-centaur, etc.

I don't know why, but I really don't like it when people invent nonsense names when they could just use regular words like "deer-centaur," "octopus-mermaid," "winged unicorn," etc.

Sorry for the repetitive and probably pointless posting. I'll try to do better next time.