Manners were for lesser creatures. A Greeed didn't need manners. He bolted up after the coin, grasping it in his hand right at the moment that Joji reached out and grasped Ankh in kind. "Hnnngh! What do you think you're doing?!"

He absorbed that 'coin' into himself, and it gave him an ounce more of strength with which to try and struggle. There's energy gathering up in his arm, too, red and angry.