I would say to find Giga by using hunt giga that’s how I found my 19 giga all of them muteadted by 2 females and 1 male btw u will need 4 giga sized gates and giga sized gate doors to trap it by leaving on unlocked and the rest locked as the unlocked one will stay open for the giga to pass tro and then close the unlocked gate way and then get on ur giga sized gate way and then start training ur way to secession and Alfa
If one is encountered near water, you can simply lure it out to sea with a flyer and it will swiftly drown. Given the water is deep enough. If encountered inland not near water. Pray to the overseers you have something fast enough to out run it. Then promptly die because they're as fast as a mad Hispanic mother with a shoe. Not as deadly as one though.