Making an object looks like is over another

Im trying to remake the material of a videogame character named rippley (from fortnite).
in unreal engine the material is set to opaque, in the head he has a blob face that it’s behind this jelly like thing, the material makes it appear in front of it to make a fake transparency effect, i was wandering how to remake this in blender
here’s a video of how the character looks like https://www.youtube.com/watch?v=i0SDF5b0Cxc