Slender at 6 feet 2 inches (1.88 m), 162 pounds (73 kg), he received extensive press coverage for both on-field and off-field controversies.

He was arrested for cocaine possession in his native Dominican Republic in January 1984 and spent three months in prison although his ultimate sentence was only a fine of $1,000.

While it is customary for pitchers to walk back to the bench after completing an inning, he would run full speed to the dugout (gold chains and long, curly locks bouncing) after an inning-ending strikeout.

He had just received his driver's license and earned the nicknames "Perimeter Pascual" and "Wrong-Way Perez" after missing a start on August 19, 1982, while circling Atlanta's Interstate 285 (a beltway) three times looking for Atlanta–Fulton County Stadium, he ran out of gas and arrived at the ballpark 10 minutes late.

After signing a minor league contract with the Expos in 1987, he joined them in August and finished the 1987 season 7–0 with an outstanding 2.30 ERA.

Pérez was found dead in his bedroom in San Gregorio de Nigua, Dominican Republic, on November 1, 2012, after being hit on the head repeatedly with a hammer in an apparent robbery.