The Grisoldians were a species that faced the Luxans in battle at some point in the past.
When Aeryn Sun questioned Ka D'Argo's strategy about hiding from a search party while on Denea, she compared it to the Luxan retreat from the Grisoldians. D'Argo retorted that "Those monsters murdered thousands of Luxan women and children. We had no alternative but to retreat. We soon took our revenge." Aeryn noted that their revenge included murdering the Grisoldian women and children. ("I, E.T.")