ALTERNATIVE METHOD (for mobile)

kill it

revive it* (at obelisk, preferably green)

make it fall off the cliff while you stand at the little platform just above that

tranq it while it tries to bite you (youre in the range of the bite, but you wont take dmg and the giga wont run away once in a while)

*average giga implant costs 24 amber, max takes 48