The general consensus among creature handlers post - CU is that a triple of Female Nargalatches is the best way to go.
At CL 22 they have 7K+ health, 300+ damage. While their low level means they take more and deal less than a higher level creature having three out at the same time is better for both tanking and damage dealing than any high level pet available. Normal CL22 creatures have around 3K ham and do much less damage. The reason their stats are so good is that they are Elite (kind of like group creatures in other games).
Fortunately, they are easy to obtain.
Step #1 Finding them
They spawn on Naboo, out of wild Nargalatch lairs, with both normal and female Nargalatches. The females are significantly stronger than the males and bear the Elite designation of having <> symbols around their names. I found lairs near the Nargalach cave POI, but the POI itself does not spawn them (you must find an actual lair to get babies). Another good spot is right in the middle of the Naboo map, just south of Karena star port.
Step #2 Taming
Use the usual technique here. If you see no babies, kill off all the adults around the liar. Then you can either tap the lair quickly, or you can ride 300 meters away and then come back. You should get a new spawn. I was able to get 4 females from only two lairs, often getting two babies on one spawn.