From here: http://doge-sucha.com/2018/12/zaregoto-1328/
I've seen this before on slangy dialogue but I can't find a dictionary meaning for it. Thanks.
This should be a variant of がつがつ or がっつり. The person in the video uses onomatopoeia uniquely, and you should not seriously worry about its literal meaning in this case. It's used merely as a vigorous-sounding onomatopoeia and the meaning of "greedy" is not important. パラライカ is also a meaningless 地口. ガッツリーナ in the latter half of the video is also in the same vein.