If you came of age in the 1980s, you remember Chunk.

The loud Hawaiian shirt.

The now-iconic Truffle Shuffle. And the endlessly endearing whirlwind who effortlessly stole every scene in The Goonies.

But the real story — the one behind the character — belongs to Jeff Cohen, and it may be one of Hollywood’s most unexpected reinventions.

From Child Star to Pop Culture Icon Jeffrey Bertan McMahon was born on June 25, 1974, in Los Angeles. His early years were marked by change; when he was just seven or eight, his parents separated — a formative moment that shaped him. Not long afterward, he adopted “Cohen,” his mother Elaine’s maiden name, as his professional surname.

Long before his breakout performance, Cohen had already begun building television credits. In 1982–83, he appeared on the CBS game show Child’s Play, helping contestants decode clues. By the summer of 1985, he was back on television as a young celebrity guest on Body Language. Then came The Goonies.

Directed by Richard Donner and produced by Steven Spielberg, the adventure-comedy followed a group of kids on a treasure hunt to save their neighborhood. In the middle of that high-energy chaos stood Chunk — loud, loyal, and unforgettable.

The Truffle Shuffle alone secured Cohen’s place in pop-culture history.

A lesser-known behind-the-scenes detail? Cohen was battling chickenpox during filming. Concerned he might lose the role, he stayed quiet and continued working. According to DVD commentary, observant viewers can actually see the spots during the famous dance scene.