real life infest human homes and are often regarded as pests. Cockroach : Fine size. Poor manipulation. +2 Con, +2 Dex, -2 Chr, poor Strength. Gecko : Diminutive size. Average manipulation. +2 Chr, +2 Wis, -2 Dex. Mouse : Diminutive size. Good manipulation. +2 Dex, -2 Con. Rat : Tiny size.