Trapping them is costly, though you can use Metal Build boards they're hitbox are high enough to which the Giga can't walk through them, place them in a sqaure formation and leave enough room in the middle for the Giga to fit, place a bear trap lure the Giga inside of the trap and swiftly place the last Build Board behind it so it doesn't get out. (Be vary of the landscape, it's detrimental)