If u want to tame this beast. You have two ways

Passibe taming and violent taming

Violent taming:

Find a giga and trap it with 3 metal dinosaur gateways and bear trap in the middle. Lure the giga, it will step on bear. Now quickly put the 4 gate way on the opening side and knock it out

Put food of ur choice and feed it large amount of narcotics

Passive method:

Apply bug repellent(giga wouldn't get agro on insects)

Go to the giga face and feed it a soothing balm(for faster result)

Now u can feed it the food of your choice

But becareful bcuz bug reppelent duration is only 10 minutes

Hope u have a nice day