Zoro and Sanji: Friends and Rivals

Though they can behave casually and calmly towards each other, Sanji very frequently gets into physical and verbal fights with Zoro (who he refers to as “marimo” or “mosshead” because of his green hair); in turn, he is nicknamed “shitty cook”, “ero-cook” and “Prince of Dumbass Kingdom” (among other things) by Zoro.

However, when the pair fight together against a common foe, they are nearly an unstoppable team.

Despite their comical fights and rivalry, they have a brotherly trust and care between them they would never admit to, in fact the two warriors understand each other better than other crewmates.
After Wanda accidentally implied that the minks had killed the Curly Hat Pirates, it is Zoro who calms the others down by reminding them that Sanji was with them, and that he would not have let his half of the crew get killed.