In English seeing it referred to as "monkeytail" looks weird, but in my native language Dutch it's often referred to as "apenstaart" or "apenstaartje" which means "monkeytail" resp. "little monkeytail". Though more and more often it's referred to as the English "at".

(Which, as I come to notice now, is almost exactly what the Wikipedia article in the sibling comment says)

Globally it has a variety of often charming interpretations:

https://en.wikipedia.org/wiki/At_sign#Names_in_other_languag...

> snabel-a, the Swedish/Danish name (which means 'trunk A', as in 'elephant's trunk')

This one is my favorite but I am biased because I grew up to this name. Always found it a funny name though.