The Fastitocalon (non-F one), can be found at Centra-Yorn Mountains (on the beach next to the Odin sidequest entrance).
They are extremely good for powerlevelling your characters/GFs for both EXP and AP over short time. They always spawn in groups of 3 on the beach.
The pattern is, if you get 100-200 Exp, you will get 9AP, 300-400 Exp, you'll get 7AP and 500-600 Exp you will get 5AP. It might change depending on your level, I don't know. But it looks pretty consistent.
They are extremely good for powerlevelling your characters/GFs for both EXP and AP over short time. They always spawn in groups of 3 on the beach.
The pattern is, if you get 100-200 Exp, you will get 9AP, 300-400 Exp, you'll get 7AP and 500-600 Exp you will get 5AP. It might change depending on your level, I don't know. But it looks pretty consistent.