On Ilum at aproximately [720, 1173] (the very bottom of the first map) is an outdoor Boss named Graymane. He seems to only have one ability, which is a stun. His melee swings don't do a lot of damage and he has a fairly slow attack speed. The location favours Republic but I couldn't find any equivilent mob up on Empires side - all that means is that Empire players will need to spend a couple of extra minutes traveling down there.
He drops up to around 3k credits but, where the real money comes from are the lvl 49-50 drops, which range from orange, blue and even
purple! On the servers I have checked so far these items sell for anywhere between 20-150k and with a respawn timer of only 5 minutes this is a great mob to camp, whilst PvPing or even between AFK'ing.