If you're lookin to tame a giga mobile or on pc,I recomend taming 140 or so on so no regrets when you look for their melee.

(extra tip for ASA)

look for them on the volcano they always spawn in the mouth.

1.place metal gate on the entrace of the volcano.

2.place giant bear trap.

3.lure the giga and let it stomp the trap.

4.corner it by placing another metal gate behind it.

5.then shoot it untill knock out then of course feed it.

6.then boom you have a giant meat eating Iguana.