A 347-pound smoke-eater is suing his fellow Long Island firefighters for razzing him about his weight.

John Munro claims he was relentlessly harassed about his size and even had his life-saving equipment tampered with by cruel colleagues at the Hauppauge Fire Department, where he serves as a volunteer firefighter and is employed as a maintenance worker.

“Have a doughnut,” they taunted, while calling him a “cow,” or “fat f–k,” Munro’s discrimination lawsuit alleges.

They also harangued him for taking up two seats in the fire truck, according to Brooklyn Federal Court papers.

Since he joined the force in October 2017 — presumably after passing its mandatory physical exam and an agility test — co-workers joked Munro would break the pool table if he leaned on it, consigned him to a broken recliner to sit in, and told everyone to call him “Billy Bob,” a “grossly overweight” film character, he claims.

Hauppauge FD bosses ignored his complaints, claims Munro, who is seeking unspecified damages.

After he asked for an investigation, someone tampered with his rope and harness equipment, his lawyer Joshua Frank said.

The Hauppauge FD did not comment.