When an extremely fat person is so desperate for companionship (to have a significant other), they will go to extremes. He/she is hungry for love and is as fat as a hippo.
Erin: Hey, don't tell anyone this, but Analissa made out with that guy 1/3 her size. She thought she had the chance but became an angry hippo when he said no and didn't want anything to do with her. He was piss drunk and in love with someone else.
Ken: That's disgusting. She's so fat and I can't believe she went swamp ninja on him and took advantage of him. That's a hungry hungry hippo right there. Too bad she thought she was better than Enoc, he's a hungry hungry hippo too trying to crush Linda!