Take the giga somewhere isolated (preferably souther Caron island) then place some metal gates in a box big enough for a giga then leave an opening and put a bear trap in there then lead the giga in there and place gates at the opening then nick him out and put kibble or meat on it and plenty of narcotics.
I dare you to raise one!! They are savage if you got two high lvl parents (about lvl 140ish) and you get imprinting on it. The thing will become an adult with about 230% melee and basically one chomp any bronto!!! But on the down side you loose your job and your girlfriend
Make 4 metal dino gates and 1 large bear trap. Place three frames and door into an incomplete square and the large bear trap in the I between them. Lure the Giga into the trap and while its trapped place 4th down to make the square. Then just light it up with tranqs