I have to agree with the OP, the scene added nothing to the film and was unnecessary to begin with. I assume the intention was dark humor, but I found nothing humorous--dark or otherwise--about seeing a terrified cat fall into a nest of rats, screaming while it was eaten alive. I was hoping the cat would find a way out of the house and escape since it had done nothing to deserve it's fate.
And who gives an animal to someone they hardly know? And when Willard said he couldn't take it, she should've taken no for an answer. Then after shoving this poor doomed cat into this crazy stranger's house, she doesn't ask later, "How's kitty doing?" Nothing?
I really despised this movie and this foolish and contrived scene was one of the reasons. Then again, I'm one of the old timers who saw the original in the theater when it came out and really didn't think it needed to be remade to begin with. I was right.
Signatures annoy me.
Not only is that scene totally unnecessary, but it's downright heartbreaking. The feline tried so hard to escape and nearly succeeded, but stupid Ben...argh! But then, I do have a soft spot for cats.