Here is an example of the knife being used. ASMR - Energy Ice Cream Rolls Oreo | How To Make An Energy Drink Out Of Ice Cream || Chinese Food  Notice it is similar but like a cleaver. I have also been trying to find the name of this, but the closest I found was a Japanese menkiri. Hope someone can answer this. PS: it is similar to the knife that was used by BanBan from one piece anime, which was asked by another user. What kind of cooking knife is this? Updates: I just found a clearer view of the knife at 3:58 in the video in the youtube link. Basically, it is like a cleaver, without the handle jutting out, but part of the blade it self.  It should look something like this: I tried to use google image search, using this image, to find but no luck.  PS: The photo above is photoshop of what I think the cleaver looks like. 
I also believe the style of knife you're looking for is called an "ulu" though the OP pix look to be a ulu cleaver. Here is an ulu more similar to the OP pix: https://www.kitchenknivesonline.com/products/12-ulu-chef-knife-walnut  