Just a bit of Potter Magical Creatures knowledge comin your way:
According to at least one Care of Magical Creatures Professor and a certain Magizoologist - a baby unicorn is called a
foal. Looks like they're not born with horns:
From Goblet of Fire:
"Today he had managed to capture two unicorn foals. Unlike full-grown unicorns, they were pure gold. Parvati and Lavender went into transports of delight at the sight of them, and even Pansy Parkinson had to work hard to conceal how much she liked them.
‘Easier ter spot than the adults,' Hagrid told the class. ‘They turn silver when they’re abou' two years old, an' they grow horns at aroun' four. Don' go pure white 'til they’re full-grown, round about seven. They’re a bit more trustin' when they’re babies ... don' mind boys so much ... c’mon, move in a bit, yeh can pat 'em if yeh want ... give 'em a few o' these sugar lumps ..."
And from Fantastis Beasts and Where to Find them
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