Arguably, this trope has existed for as long as we've had literature. You can look at a very early version of this in Gilgamesh - Enkidu is the wildman whose actions are at odds with Gligasmesh's civilized ways.

More in my wheelhouse, you have Hreiðarr of Hreiðars þáttr and the way his brother Þórðr deals with him, as well as the way which Magnúss konung reacts to his rustic ways.

To help out, the terms you are looking for are "straight man" and "funny man."