Doc Ock's powerup
Oh yes...Dr. Ock and his powered-up adamantium arms. In the very next issue, Ock used those arms to pummel the crap out of the Hulk and make him look like a chump...which caught the ire of Mr. He-Who-Shall-Not-Be-Named, who was writing the Hulk at the time. Larson has been beefing with him ever since.