"Explume is lost to the Lugubraa, six hexes be upon them. Cloak and evacuate the nestlings while I – Awwwwkk!"
―Shell Conjurer Firtha's last words[src]

Firtha was a Croke who lived in the Croke Reach in the Unknown Regions. He had attained the rank of Shell Conjurer and lived on the Croke colony of Explume Minor.

At one point in their past, the Croke suffered greatly during a long civil war amongst themselves, a conflict centered in the Croke Reach. The situation worsened greatly after one of the factions introduced the voracious Lugubraa, a common mercenary species of the Unknown Regions, into the area's worlds. Many Croke settlements were destroyed by the Lugubraa, who reproduced at an alarming rate, and soon began to feed out of control. The Croke, in an effort to wipe out the invasive species, purchased genetically modified Lugubraa, known as blind berserkers, from the cloners of Kamino. These clones, however, proved to be just as problematic as the original Lugubraa, and caused further devastation to the Croke Reach.

Explume Minor was one of the colonies attacked by the Lugubraa, and Firtha's last transmission was to order the evacuation of the Croke nestlings from the colony. As he spoke, he was overwhelmed and killed by the attackers.