Haros grew up on in a small town or settlement, most likely on the Krill homeworld. Evidently, religion profoundly impacted Haros as a boy; he later commissioned architects to build an exact copy of its chapel in the Yakar.
As captain of the Yakar, Haros led a raid on the Union colony planet of Chara 3, killing the colonists and plundering its resources.
In late 2419, the Yakar received orders for what would be its final mission. The ship was fitted with a prototype weapon to be tested on the Union planet Rana 3. En route to the planet, the Yakar picked up Chris and Devon two survivors of a recently destroyed ship, the Kakov. In reality, Chris and Devon were Union spies named Ed Mercer and Gordon Malloy respectively.
Chris and Devon sabotage the Yakar's lighting system to emit an intense burst of light. Krill are extremely sensitive to UV radiation, and the subsequent burst burns Captain Haros alive.
Captain Haros is a stern and religious man, dedicated to following the teachings of Avis found in the Anhkana. For that reason, Haros is responsible for horrific attacks against non-Krill species, killing the colonists of Chara 3 and planning to do the same to Rana 3. The attacks are a means of furthering the Anhkana's agenda to obliterate all other life.
Haros enjoys religious services held each day. "It is a welcome break from our duties," he tells Chris and Devon. "And a reminder of our place in the universe and in the eyes of Avis."
Before their deaths, Haros was an old friend with the high priest of the Yakar, Sazeron. He describes Sazeron's personality as more suspicious than his, but Haros trusts his comrade's judgement. Indeed, Haros is trusting to the point of naivete. Even after Haros comments that "Chris" and "Devon" are strange names in Krillain, he accepts the two's explanation that they were "conducting maintenance on a shuttle" when the Kakov was destroyed, replying, "We are pleased to be the answer to your prayers." Later, when Chris and Devon are found in the chapel, Haros asks Sazeron, "Is that not a good thing?"
- Despite having a unique name he is specifically listed as "Krill Captain Haros" in the official credits.
- Haros enjoys the Human aphorism "rank has its privileges" as a wise observation.