R-55 was a police droid on Vorzyd V. In 1 ABY, R-55 responded when C-3PO called out for help after Luke Skywalker and Leia Organa had been captured by Blackhole troopers. R2-D2, however, tricked R-55 into believing that C-3PO had a malfunction so as not to reveal Skywalker and Organa's secret mission to Vorzyd V. Suggesting that C-3PO report to the local repair center, R-55 left again.
Moments later, when a group of Freelies tried to steal C-3PO, R2-D2 called for R-55's assistance, and the police droid responded by chasing off the criminals.