A couple has a baby boy born without a body... (A Two-Parter)

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Part 1
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After years of trying to conceive, a couple finally manages to have a baby. However, the baby is born with only a head, with no body, arms, or legs. Despite the setback, the couple set out to raise their child as they would any other.

After ten years of challenging child-rearing, the couple decide to take a much-deserved vacation to Hawaii. On the beach in Maui, they meet a rather eccentric doctor. After describing their son's condition to him, the doctor tells the couple about an experimental treatment that may help the boy grow limbs.

Overjoyed, the couple rush home to deliver the news. Upon entering their son's room, they declare, "Honey! We have a wonderful surprise for you!"

The boy rolls his eyes and says, "Oh great, another hat."

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Part 2
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Eleven years later, the boy has grown up. The doctor's experiments having failed, life proceeded as normally as it could have for the head-only boy. On his 21st birthday, the father decides he's going to take his son out for his first drink.

They arrive at the local bar and the father gently places his son on a barstool.

"Bartender! A shot for my son on his birthday!"

The bartender pours the shot and the father lifts it to his son's lips. After drinking it, the son miraculously sprouts a torso.

The old wino at the end of the bar yells, "Serve him up another, barkeep!"

Another shot is poured and given to the boy. He immediately grows a pair of arms.

"Another!", shouts the wino.

The boy holds it himself and drinks; he grows a set of legs.

He stands up and takes his first shaky steps on his new legs around the bar. Soon he is skipping and jumping, everyone in the bar is cheering; the boy yells, "Father! I can walk! I can walk!"

Blind with glee, the boy runs straight out the front door and immediately gets hit by an 18-wheeler, killing him instantly.

The old wino at the end of the bar rolls his eyes and says, "Shoulda quit while he was a head."