I've a 150lt tropical aquarium with a very mixed community. I'm looking for something new and unusual. I've the usual suspects already, betta, guppies a couple of different loachs, shrimp, glass catfish and a rope fish. I'm half thinking a crab or crayfish but I know they will eat the plants and slow moving fish. Any body got suggestions. I want something non aggressive but not a hider. I want my multiple plants to survive and the slow lazy fish to stay slow and lazy rather than dinner. The more unusual the better.