While waiting for Luffy to finish his talk with a traveling merchant, Zoro started glaring at the merchant. He's just too overprotective.

Robin comes up to Zoro, "Zoro-san have you heard the talks about you being Luffy's 'Blood Thirsty Guard Dog from Hell'? It strikes fear in people."

Zoro smiles a bit. He likes what he's hearing, it should be warning to people that they shouldn't go near Luffy but him.

"Blood Thirsty Guard Dog from Hell?" Zoro pauses then smiles devilishly.

"I like it."