Three Incidents That Gave Kamsa Ample Warning About Krishna

"The Trinavarta demon who took baby Krishna on his shoulder went high in the sky, but the baby assumed such a weight that suddenly he could not go any further, and he had to stop his whirlwind activities. Baby Krishna made Himself heavy and began to weigh down the demon. The Lord caught hold of his neck." (Krishna, The Supreme Personality Of Godhead, Vol 1, Ch 7)