If it looks like this picture from Frank Magallanes it is not a Goliath, but instead it is a juvie H. vittatus. the one in the pic is described as about 5" long.
Beasty looking. Wish i could own 1. From the pic, it also looks like there's no red colouring on the tip of the tail? How bout brevis? Anways to spot a brevis? Shorter snout?