Reindeer are a little unusual among deer. In most species, only males grow antlers, but in reindeer, these big old head bones are a perfectly normal feature for females, too! And how and why they grow antlers is rather interesting...
On his busiest day of the year, spare a thought for poor Rudolph, who is doing all of this while he's pregnant https://masto.ai/@vagina_museum/111527709965898718