 Jackals , or Kig @-@ Yar , ( from the moon of Eayn , orbiting Chu 'ot ) carry energy shields or ranged weaponry . Shield or armor colors denotes the rank of each caste . In some cases , such as with the Jackals , the overall design was honed once the enemy 's role was clearly defined . They look like bird @-@ like creatures or raptors . This particular species did not come into the Covenant in the same way as other species . They work as mercenaries , as their culture is based on piracy and do not follow the religious beliefs like the other species . In the Halo book , Halo : Contact Harvest , it was revealed that Jackals were the first species in the Covenant to encounter humanity . The resulting events initiated the start of the Human @-@ Covenant War . 
