Collision detection on large animated characters

Howdy,

I'm wondering how I could implement 3d collision detection such that the player character can traverse a giant moving character. I tried using the combination of general 3d colliders method however, this seems to be too inaccurate since the giant model has curves and such. Also, I have read online that mesh colliders are only for static objects. So I am stumped. How can I do this? Perhaps, this can be done through scripting?

If my description is not detailed enough please refer to the gameplay of ps2 game Shadow Of The Colossus. That is close representation of what I aim to do.