The Jackal is the first standard Corpus boss that the Tenno can encounter, at Fossa on Venus. The Jackal is a large, quadrupedal proxy whose existence poses a threat to Tenno activities in the area.
Lotus: "In an attempt to exert power and authority, the Corpus have continued to refine their most lethal security proxy. The Jackal. Determine its location aboard this vessel and destroy it."
Lotus: "Every warframe has at its disposal a special blade: a Parazon – as lethal to technology as it is to flesh. Disrupting the Jackal's auto-repair may require it."
(upon entering arena) Lotus: "Remember, the Jackal's auto-repair precepts could make this a battle of attrition you will lose. Watch for an opening and remember your Parazon."
[The circular door set into the floor opens and a platform rises out of the ground, as red strobe lights flash and alarms sound to announce the commencement of the weapons test. As the platform clears ground level, its cargo is revealed: a tiny Test Moa.]
Lotus: "I expected it to be… bigger."
[The Moa begins to step forward, but is instantly crushed by a massive machine crashing down from the ceiling. Segments unfurl and swivel as the quadrupedal combat proxy activates and assumes a combat stance, uttering a mechanical roar as its shields power up.]
The Jackal will say these lines during the fight.
"Trivial threat detected."
"Kill chamber sealed. There is no place to hide."
"Enemy analysis: Organic. Threat level: Impotent."
"Pathetic organics require sterilisation."
(when damaged) "Metrics error. Threat requires escalation."
(when damaged) "System degraded. Adjusting confidence intervals."
(when damaged) "Auto-repair in progress. Combat precepts halted."
During the fight, the Lotus will direct the Tenno on how to effectively take down the Jackal.
Lotus: "Massive flex-plates on the torso… but appendages could be a weakness."
(when a limb has been damaged) Lotus: "Still mobile despite the damage, but if it comes down hard, it could give you an opening."
(when the rotating grid-wall is active) Lotus: "Lucent grid-wall! Stay ahead of it!"
(when the Jackal slams to the ground and is stunned) Lotus: "Tenno! Use your Parazon!"
(when the grid-wall takes out the pillars in the arena) Lotus: "Watch your angles, Tenno. You're running out of cover."
(during the third stage of the fight) Lotus: "Overdrive precepts. Watch for increased attack speed!"
(when the Jackal is stunned during the fourth stage of the fight, variant) Lotus: "Critically damaged. Finish it off."
(when the Jackal is stunned during the fourth stage of the fight, variant) Lotus: "It's sending out distress waves. You know what to do. Destroy it."
(after the Jackal is defeated) Lotus: "Well done, Tenno. You have sent a clear message to the Corpus today: their war profiteering will not go unpunished."
Like many of the Corpus bosses, the Jackal is not a true character, but a robotic proxy that can be replaced. It does not seem to have much of a personality, and standard Corpus protocols would ensure that its AI capabilities are limited.
The Jackal fight underwent a radical redesign with the release of Update 28, with minor appearance changes to the boss as well. The Lotus' dialogue during the mission makes clear that this redesign is canon, representing further technological development of the older Jackal model. This new Jackal is also seen during the New War quest, as well as a Corrupted version in Duviri's Undercroft.
The older Jackal model is somewhat ubiquitous in Corpus locations. It can spawn as a field boss on the Orb Vallis at high alert levels, including as an Eximus version. The Orb Vallis is, of course, located on the same planet as the upgraded Assassination mission on Fossa. The Razorbacks, first appearing in the Divine Will Tactical Alert and now recurring sporadically, appear to be upgraded versions of the Jackal. The Lynx, a field boss that can appear in Void Sabotage missions and some Grineer data vaults, appears to be a variant of the Jackal as well. In addition, Jackals can be seen in production in the Gas City on Jupiter (and mentioned on Alad V's broadcasts) and on the Infested Corpus ships in the Eris sector. Lastly, a Jackal is the centrepiece of the Energy Lab in the Tenno Dojos, being dissected and studied. All these appearances feature the older Jackal model.