R3-D5 was an astromech droid, that was active during the Clone Wars. He appears as a minifigure in the 9498 Saesee Tiin's Jedi Starfighter Lego® Star Wars set. This set was released in June, 2012.
R3-D5 was the second R3-series astromech droid to be featured in Lego Star Wars. The first one was R3-S6, aka Goldie, who appears as a playable character in the LEGO Star Wars III: The Clone Wars video game.