Not sure if they are considered monsters, but I keep Frontosa's ( Kigoma, Mpimbwe, and Burundi ). I also keep Tropheus ( Katoto, Kachese ), along with Altolamprologus compressiceps (Gold Head), Altolamprologus compressiceps (Fire Fin), Ophthalmotilapia ventralis ( White Frost ), Synodontis ( Multimaculatus, Petricola ).