The howlers are a race of artificial beings from the 'Animorphs' book series by K.A. Applegate.
Biology
Howlers are about the same size as large men, their skin resembles half-cooled lava, while their eyes deeply contrast it with a deep robin's egg blue. On their wrists they have a set of retractable claws very similar to Wolverine's. Abilities include: a paralyzing howl, hence the name howlers, seeing through the skin of targets to find vital organs, tracking a prey item's trail, and swiveling their waists 360 degrees. They have an lifespan of seven years but the entire species possesses a collective memory to whish allows them to draw thousands of years worth of battle experience.
History
They were created by an all-powerful being known as Crayak. Howlers were designed as a sort of biological weapon and were created because Crayak believes that the weak should be eliminated by the strong and the strong eliminated by the stronger still. When Crayak made the first seven howlers, he made their minds reminiscent to a small child's so that they would think that killing and war was a game and that other races were nonexistent. However on the Iskoort homeworld Jake showed one that others actually had meaning, and more importantly, love. Howlers have a collective memory feature for spreading battle tactics so when Jake showed that howler those feelings it got into the collective memory so the next seven howlers would know everything Jake showed that one howler.
Culture
In addition to that howlers usually carry a small arsenal of weapons including dracon beams, metal shard guns, daggers, and poison balls. They have the mentality of children, making them easily impressible, taking enjoyment in murdering and killing due to the only concept that have been exposed to since their creation.