Yea I remember google searching this like a year or so ago and a pegasus does not have a horn at all. Alicorn is da correct word for it but I know alot of people called it as pegasus not knowing what it actually is called. So every time I see a Alicorn in webtoon or manga and its being called pegasus. I laughed cuz they didn't do their research right on da specie
To be fair, pegasus is technically the most well known species since it's based on a Greek myth. Alicorn is a new recreation of the mythical being, mentioned in my little pony and other shows as I've researched. Alicorn on ancient texts doesn't even mean a horse with both wings and a horn, but it's a word used to describe the medicinal properties of a unicorn's horn and in general the horn of a unicorn.
That's a pegasus, not a unicorn.