KAT & Roman Kostrzewski

Kat & Roman Kostrzewski ("Kat & RK") was a Polish thrash metal band formed by Roman Kostrzewski and Ireneusz Loth after they had left their original band KAT in 2004. Some of the fanbase of KAT views Kat & Roman Kostrzewski as its successor, mainly due to the characteristic vocals of Roman, his lyrics and choice to sing in Polish as in most of KAT's original albums.

Since 2004 the group has toured extensively through Poland, while composing material for their first album Biało-czarna" (White-and-black), which was released in April 2011 by Mystic Production. The first samples off the new album were released in late 2010.

On February 10, 2022, Roman Kostrzewski died of cancer at the age of 61.