Black Cat-class subprowler

Black Cat-class Subprowlers are a classification of small exfiltration ships within the United Nations Space Command. Designated as "sub-prowlers," they have extremely limited capabilities and are used mostly as exfiltration craft to escape combat situations with stealth and ease. The ships have slipspace capacitors, but only enough charge to use them for about four hours. Black Cats are routinely used on high-risk ops, so that UNSC Special Forces can retreat quickly and easily. Each subprowler can hold approximately 38 SPARTAN-IIIs.

It appears that they replaced the Calypso-class Exfiltration Craft.

Eight such craft were inserted for the Spartan-IIIs during Operation: TORPEDO, but only one was used because only two Spartans survived the engagement.

The Black Cat classification is believed to be smaller than the standard UNSC Prowler.