The -ak is a plural, so it's just "those koxkorrak"

I haven't studied Euskara but I do enjoy its look.

Highly recommend the music of Fermin Mugurunza and his old group Negu Gorriak to those enjoying punk, ska-punk and dub. Buy the actual CDs (will have to be online, I don't think you'll find them in shops unless you go to Spain) and you'll get the lyrics translated into English, French and Spanish.

Fermin's a leftist Basque separatist and is more than slightly doctrinaire but I love the energy.