Here is my giant! She is about 13-14lbs and VERY VERY friendly. She likes to try to play with the dogs, but they are nervous of her. Dexter barks at her and she charges him... she's at least 2x his size. Fletcher lets her near him but he looks at me like "Mooommmm.... get it awayyyyyy from me!!!" LOL
I only let mine all out together because my bunny is hearty (not faint of heart) and as big as the dogs! If she were smaller or more nervous they wouldn't be out together, trust me!