Also known as: 親子かめはめ波
An iconic moment from the end of the Cell Saga in Dragon Ball Z, where Son Gohan, and the soul of his deceased father, Son Goku, combine their powers to fire the Kamehameha (Dragon Ball) that would ultimately defeat Perfect Cell.
Referred to as the "Parent-Child Kamehameha" in Japanese; so while the English name specifies a gender, it's gender-neutral in its original Japanese, so parodies often run the gamut of all parent-child combinations.