prerušiti

1. (prerušiti se u + acc.) to disguise oneself; to dress up
   Za maskenbal se prerušio u gusara. — He dressed up as a pirate for the costume party.
   Lopov se prerušio u poštara. — The thief disguised himself as a mailman.
2. to disguise; to dress up
   Prerušila je sina u Deda Mraza. — She dressed her son up as Santa Claus.

Mostly used with se: prerušiti se u nekoga.