this should be possible but it might be expensive and a little tricky and time consuming to set up.
firstly in your construction script you can access the vert positions of your static mesh (https://answers.unrealengine.com/questions/465484/how-to-get-vertex-xyz-from-static-mesh-via-bluepri.html)
then you can pass the blueprint a set of vert numbers and get it to create a spline component from those verts
then you can just animate a mesh along a random spline to get the effect you’re after.
you might get some strange movement if you have a very low poly mesh but i dont think you could start to curve things without the animated mesh losing contact with the source mesh at some points.
if you set up a few debug tools - like an option to add a text render at each vert location and a preview mesh to the spline etc. then it shouldnt be too time consuming to add the spline, but if you wanted something like spiders you’d probably end up using quite a few to create randomness…
also you’d be having to update all the spline points every frame, presuming the mesh was animated…
maybe a better way to do it would be just to store and update the vert locations every frame and then just lerp the spider mesh from one to the next nearest without returning to one thats already been visited… not sure what sort of visuals that would give, but you should be able to create some heuristics that weight it more to a particular direction, although you might find you get a sort of gridding effect around the edge loops if you’re using the vertex locations…
so in summary the best way to get this sort of effect is probably just using a scrolling map on top of the mesh, but if you really want meshes to crawl over other meshes there’s probably a complex and expensive solution you could set up.
actually if you wanted more 3Dness than a scrolling material you could model in strips of polys over the mesh and then have your spider texture scroll over that - a combination or crossed mesh should give you a decent result. depends if this is for gameplay or cutscene etc.
hope my ramblings sort of helped!