This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
猽 combines the animal radical 犭 with 冥, which likely contributes a phonetic element. The exact historical development and original meaning are uncertain.
The animal radical 犭 suggests a creature, and 冥 can mean dark or obscure. Picture a mysterious animal lurking in the dark, its meaning hidden.
For ベイ, imagine a bay where a strange animal hides in the dark: bay -> ベイ.
—