Those Not of the Blood... must have their blood spilled. Or, so translates the Kilrathi: Va ka garga ka naru ha garga. Though it may not have fared well against the Hoe of Destruction, the Bloodfang was decidedly Kilrah's finest. The Bloodfang-class Superfighter first appeared in the non-playable Wing Commander II Demo (available here). Prince Thrakhath flies a Bloodfang - rendered in WC1-style graphics - to deliver news to the Emperor.
The fighter appeared again in Wing Commander II, again in the hands of the Prince. You encounter the ship only once, in a one on one dogfight against Thrakhath at the end of the game -- either in K'Tithrak Mang D or Gwynedd (2) D. The Wing Commander II version is identical to that which appears in Ultima VII.
The Bloodfang appears a third time in Wing Commander III, significantly redesigned with the modern 'non-symmetrical' approach to Kilrathi fighters. This time around you see them twice: when Thrakhath taunts you with Angel's execution at Torgo 3 and then again in the game's penultimate dogfight at Kilrah 3.
The fighter received its name in Wing Commander 3, as well. While Wing Commander 2 refers to the fighter as Bloodfang internally, the name was not entered into the continuity until it appeared in WC3. It was not spoken in dialogue until the release of WC3 3DO, which restored a missing 'news brief' segment about the fighter (available here). The Bloodfang also appears as a rare WC:CCG card, representing Blood Most Noble Squadron (motto: "The Emperor's Chosen"). You can see a complete set of specifications for both Bloodfang variants here.