What animals are so rare and evasive that they are practically never photographed filmed or even sighted? Just name me some.?

Even Mesonychoteuthis hamiltoni (Colossal Squid) has been photographed, including live specimens. Photographing, filming or even seeing rare and evasive species is going to be by its very nature challenging. If a species is rare, evasive or both then opportunities for obtaining still or moving images will be both few and difficult. There are species for which there is little photography but I cannot think of an animal that we know of for which there are no images.

Wolverines. Panthers...Bigfoot

Bigfoot

I came to this question hoping to be the first to mention giant squid and colossal squid. A couple beat me to it.

I offer one of the most elusive land animals - Snow leopard of the Himalayas.

Do ghosts count as animals? ;^)

The only one I can think of off the top of my head is the colossal squid, but I'm sure there's tons of others. Especially in the ocean, since there's only so far we can go, not just man himself but even our technology, before the pressure gets so high it starts crushing stuff and cutting off signals and whatnot.

Seagulls, pigeons, dogs, cats, mosquitos, flies