First, She sooo looks nothing like a rat. My husband thinks Yogi looks like a gremlin. Which is fine, because I've seen that movie, and I thought they were cute

!
I've had a couple people make comments like that about Yogi, when I'm walking him, like "look it's a guinea pig!!" or "he's not even a mouthful for my dog

!" (the one that said that was walking his boxer.) and yes, some guy at a local campground asked me if Yogi was a rat. I was so infuriated, so I know exactly how you felt. I was so mad, that I couldn't even say anything in return. My husband said that the next time someone calls Yogi a rat, he's gonna tell them "well, by the looks of you, you have a lot of experience in that area."
But mostly, most people just love him and I get a lot of compliments. So I just try to put the negative ones out of my head and thank God that I have him!!