I searched for Sambas a couple of times... Asking around if someone had tamed him to think about what the best time is to start looking for it... I searched for 2 days for around 2-3 hrs... A guildie of mine whispered me then he found Terrorpene. So I went down to Hyjal to tame that one instead. 30 minutes later an other hunter in our guild got Sambas when he was fishing. I think you can't really search for a rare pet. You just have to be at the right spot at the right time. Just pure luck!