Must I fulfill a vow to slaughter a "chick" that cannot be eaten, especially if the vow was made during adolescence and in jest?

As long as the vow was made before puberty, it is not obligatory to fulfill it, according to the hadith: "The Pen has been lifted from three: from the sleeper until he awakens, from the insane person until he regains his sanity, and from the child until he reaches puberty." Eating chickens is permissible. In the hadith: "No human being kills a sparrow or anything larger than it without its right except that Allah will question him about it." It was asked, "And what is its right, O Messenger of Allah?" He said, "He slaughters it and eats it, and does not cut off its head and throw it away."