Most, but not all, panthara require a trick to tame. Farm up some Fresh Talbuk Meat
which is drops rarely from talbuks on Argus; approach your target; throw a Freezing Trap; Feign Death to lose aggro (this is essential for the meat to work); throw the meat directly on top of the panthara; tame quickly!
Panthara that do not require this trick are Naroua
, and the Shadow Stalkers
in The Seat of the Triumvirate dungeon.