Print this model in TPU filament to get the flexible aspect.
In fusion360 you can alter the design as you wish, there are a lot of parameters to tweak.
Note: Due to the technique I used in the model a warning can pop up in the timeline after some change (example if you change the length). If that is the case you can probably either ignore it (it should still work) or easily fix it by simply right-clicking “modify” and then clicking ok without changing anything. Sorry for the inconvenience, i didn't found a way to remove this warning but if you do please inform me, i would love to learn.
The author remixed this model.
I remade this model in fusion360 and made it parametric. I added a tongue as well to make it a snake. I finally also took notes from the comments to improve the design as well.