Weird Slicing Effect... what is this?

[tinto]

I own a Flashforge Creator Pro and I'm pretty new to 3D printing. Some models look very odd after slicing and I don't know what the underlying cause is, or how to fix it. I'm also not sure what the term would be for what I'm seeing here, which is making it really hard to google/research. This is happening in FlashPrint.

Can anyone give any advice on what is going on here and/or what I could do to fix it? Failing that, any tips on what I could search for in order to research more?

I've attached an image of the model in FlashPrint both before and after slicing.

dwarf_model.jpgdwarf_sliced.jpg

Thanks