I've never known a Garg so far to be aggressive yet. I've got 9 of them, all varying ages (3 months to 2 1/2 years) and I've never been bitten. They're quite a bit calmer than Cresteds are, I find. Also, when Gargs are younger, expect to have little cricket monsters. All of mine went absolutely crazy for crickets and still do. They can be picky eaters with CGD, so if you've got multiple flavours try them all out. I have one male that loves mango and the other wont have anything to do with it so they do have their own preferences.
Gargs also tend to go after larger prey items, so if you find he/she is not going after the crickets, get some that are a bit on the larger side and see if that makes a difference. None of mine were ever impressed with tiny crickets lol, they're pigs that way.
All the best and congrats!! I can't wait to see pictures!! :biggrin: