Well to stop people crying, I will rephrase what I said.. since I have played they game they have always lost health after taming out and I have been playing for like a year or so.
Gigas usto half stats when they came out from wild to tamed they usto come out with higher health n higher stats but they nerfed cause they were to op. Long long time ago. Then the wild gigas got stat increase they all at 80k ish health wild but they tame bout 17k
They still do massive damage. The percent on dinos are weird. Just cause it shows the rex dino melee higher does not mean it hits harder than the giga.