Maybe one could be called a “Harrison Withers”, after the guy like this in Louise Fitzhugh’s book Harriet the Spy.
I suspect it wasn’t particularly intended as humor. Animal hoarding is a recognized problem, and so a person - male or female - who has more cats than they can realistically take care of is rightly called a cat hoarder.
Felix Dementis
Like this guy?
I immediately thought, “Engineer”
This may be apposite, try googling ‘Steve Bowen and Bob the Cat’ homeless busker who has adopted a Cat who he takes with him while busking in London.
Quite a heart warming story but rather un-catlike behaviour,
Peter
Awesome.
By the by, the definition I read here at SDMB once for crazy cat lady was “having more cats than you have teeth in your head”. I thought that was quite good.
I call myself (a male) a crazy cat lady. The term’s meaning never seemed to particularly rely on the sex. No one looked at me strange—well, no stranger than anyone would look at someone who would willingly adopt a title of derision.
I do not live in my parents’ basement!
Their RV doesn’t even have a basement
My first thought: Norwegian bachelor farmer (Prairie Home Companion). Not the cats bit, but the hermit/crazy part for sure.
They’d be ‘mad aul fellas’ here in Ireland as in ‘that mad aul fella from down the road was shouting at the kids again’.
I was thinking “Old Man [last name]” but it looks like the OP wants a feline-obsession-specific element in the title.
Might have to go with “freak” in that case. The concept of Crazy Cat Lady exists because it’s an example of the stereotypical nurturing female taken to an extreme. Stereotype Man is not nurturing, he’s mechanically-inclined, stoic and independent. The extreme of that is the expressionless, antisocial guy who’s always hammering on his roof and controlling the chemical composition of his front yard with elaborate, scientific precision; bonus points if he’s a WWII European theater veteran. Such men don’t like cats. Based on that, an old recluse with a bunch of cats is a freak. At least that’s what Old Man Montoya’s gonna call 'em in 30 years. “Goddamn freak lettin his goddamned cat into my yard to diggup my goddamned tomato plants.” (muttered while synthesizing some kind of cat trap from Coke bottles, plastic coathangers, Vaseline and string).
So basically Clint Eastwoood’s character from “Gran Torino?” 
You might need some netting for your cat trap - I almost trapped an unwanted feline in my netting for my peas this morning!
Was the cat trying to take a pea?
Artemis beat me to it: Gun nut.
~VOW
There is no debate on the number of cats that make you a crazy cat lady.
The magic number is 2.
More than 2…you are crazy cat lady.
I believe the answer is Adam West.
Before I saw that actual cats were required, I would have said “curmudgeon”.
Difference:
Dog hoarder (male variety) = curmudgeon
Cat hoarder (male variety) = furmudgeon
~VOW