Wurger
Wurger was group of Assassin-class corvettes used by the Rebel Alliance, that contained troops for Admiral Harkov's fleet. They were eventually destroyed by Imperial pilot Maarek Stele.
Behind the scenes
Wurger goes as a group of 2 corvettes which appear in 2 missions; firstly, before the Protector's departure of DS 5; and subsequently when DS 5 is captured. However, as a secret objective both corvettes in both missions have to be destroyed. This makes it unclear if there are 2 or 4 Assassin-class corvettes.