father-son kamehameha
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.
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 that would ultimately defeat Perfect Cell.
This tag implicates kamehameha_(dragon_ball) (learn more).