This results in him gaining the power of elasticity (like Fantastic Four’s Mr. Fantastic or The Incredibles’ Elastigirl), along with regeneration, invulnerability and slow aging.
Plastic Man originally started as a Quality Comics character in 1941 before the elastic-powered hero moved to DC when its prior publisher sunk.
O’Brian becomes a police officer in between his superhero antics.
As the story goes, Patrick “Eel” O’Brian was part of a gang until he is left for dead by them during a heist-gone-wrong, which left him soaked in an unknown chemical liquid.