Claws: There are two types of Yam'rii, one whose arms make large armoured blades similar to a Mantis, these blades can be used in combat for Str+2D damage. The other type has fine manipulator arms, who do not get the bonus damage, but do get +1D to Dexterity.
Hard Carapace: Yam'rii have a hard carapace, which protects them from damage, giving them a bonus +1D vs energy, or a bonus +2D vs physical damage.
Quick Tempered: Yam'rii are known for their Quick Tempers and as aggressive combatants, and are known for committing what other species consider hideous war crimes as they do not really consider other species to be anything other than animals.
Inconsiderate: As mentioned above Yam'rii do not consider other species to be anything other than animals, so will not offer them the same courtesy as most sentient species offer each other, and will happily eat the eggs and meat of intelligent species, savouring the taste of eggs especially.