They are REALLY hard to get, or at least Sambas, cuz hes really loved by hunters :/
He took me 2 months! to get.
Karoma isnt really hard, found him the 2d day of searching, and ive been spotted him 5 times in total and gave him to other hunters
Some tips for Sambas: i found him twice at 6am (st). Thats probably the hour that no one is looking for him. When i found him at 6am no one wanted him, the first time, i tamed him of course, and the 2d time i asked in general chat, and no one wanted him, untill i told a hunter in my guild. me: hey, are u interested in Sambas? rare beast tameable in Twilight Highlands. her: uhm, i really dont know whos him. me: just come here xD and tame him, hes extremelly hard to get

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and she was really slow, took her about 15minutes to get from Orgrimmar to Twilight Highlands >.> i was really nervous :/
Try to look for Sambas when its really late, around 4 - 7 am, make a macro and keep spamming it,
[ /tar Sambas /tar Karoma /stopmacro [noexists]
/tell YourName --> %t <-- ] Keep you Track Beasts and Track hidden on. Download Silverdragon and _npcscan . Sometimes ask for info in general chat. i really dont give a shit about what people think about me, i just wated my Sambas (: so i was almost spamming in general chat :b