Its called a symbiote, and it doesnt consume people, it merges with them. The symbiote is alive, and therefore you cant rip it off, because everytime you try to it just slips through your fingers. In the shows and series there were instances where Eddie Brock or Peter Parker would cut off small samples for tests, but thats about it. Also, the Symbiote isnt as fabricy as they show in the movie, although it can change its form to mimic any clothing, its usually just a smooth black suit. witht he white spider in the middle front and back.
I also found problems with the way they deplicted the symbiote moving over peter parker when he was sleeping. I found it too, i dont know how to say it, but stiff. It seemed like the symbiote wasnt as fluid as it originally was in the comics and shows. In the shows or comics, you can see the smybiote stretch itself quickly, within an instant, without stopping whenever it wants to.
like that but in the teaser, it seemed to slowly creep un-smoothly onto spiderman. I just hope they make the symbiotes movements more rapid and fluid, because by the teaser it seemed like it was slow, and dull. When in reality its very fast and smooth.