Lore Bites (& Speculation): Why Venti Hates Cats
is it possible he actually is just allergic?
i mean, yeah. i guess it's possible.
--or he could be avoidant for other reasons.
most people know about the link between cats and the Norse goddess Freyja (two big forest cat companions that pull her cart, etc.), but there are some other pieces of Northern European folklore regarding cats that may be relevant:
cat fur/skins were often worn by Germanic seer-esses (volva) because cats were believed to aid in making connections to spirits and the afterlife--much like Venti's able to do (see: Carmen Dei SQ).
in Celtic mythology, giant fairy-cats known as cat-sith acted as guardians of the Underworld, and were capable of snatching away the souls of the newly deceased if they passed across their grave early enough.
cats also have a (kind of weird?) connection to the World Serpent, the giant snake that's supposed to live at the base of the World Tree and gnaw at its roots). depending on which myths you read, Thor allegedly had a (pre-Ragnarok) run-in with Jormungandr while it assumed the form of a giant cat--and lost.
during the Witch-Panic of the Middle Ages, it was believed not only that witches kept cat familiars, but that witches could shapeshift into cats.
so while Venti might "just be allergic," he might also be
avoiding cats that are connected to dead Mondstadters/friends (out of fear or guilt)
avoiding cats that could be associated with the Dragon Sovereigns (also out of fear or guilt)
avoiding cats that might be Hexenzirkel members in disguise (wondering where the hell he's been for the last 500 years and why he won't take responsibility for his actions/come and visit their tea party)