Anime avatars are often a coin toss between (potential) comrade and chud, so it may be fun and maybe helpful to think about and share those in the place of that old 
bellwether for chuddery.
Mine is anyone with ".eth" as a suffix in their online name. I have yet to see a single person that does that that isn't a chud. 
It may even be cheating, but seeing an actual cryptofascist cartoon "original NFT do not steal" is a pretty reliable red flag too. 
EDIT: Oh yeah, I almost forgot. 
While antivax stances do exist in liberal and even leftist spaces its huuuge within the rightwing and usually comes alongside some other rather interesting "opinions".
Remember when anti-vaxxing used to be only a new age thing?
It only became a right-wing thing because their team hates vaxx now, and that owns the libs.