Nyan Cat Rainbow Bridge?

I’m trying to make something similar to nyan cat. I have a flying bird-like creature that flys around with a very simple rig and flying animation. I want it to fly across the scene in a cutscene and create a trail behind it which is a rainbow bridge that is a static mesh with a holographic rainbow material. I also want it to expand in size (width) over time. Like it should spawn like a ray or lightsaber holographic bridge type. Kind of magical beam-like.

So what I have so far is the bird with a rig and flying animation. I can make it move from spot A to spot B using keyframes. I also have a square plane with a rainbow material if that’s useful. I think I have to create a particle effect that spawns a rainbow trail with minimal fade away and it turns into a static mesh while it expands scale width over time as well.