In a shocking incident, two large hairy spiders unleashed mayhem on a Canada-bound flight as passengers screamed and stood on their seats after learning that they were sharing the cabin with the eight-legged critters. 

Two hairy stowaways were blamed for unleashing a rare commotion on board a recent Air Transat flight from the Dominican Republic to Montreal that sent passengers screaming in panic. 

Not one but two tarantulas, potentially measuring as much as 20 centimetres across, were spotted roaming the carpeted cabin soon after the inflight meal had been served on the April 18 flight from Punta Cana, a popular holiday destination, to Montreal in Quebec. 

Catherine Moreau was watching a movie on her iPad on a flight to Montreal when she felt what she thought was a wire brushing against her. 

"I brushed (it) away and it started tickling me again. 

That’s when I noticed the tarantula. I hit it to get it off me before it bit," Moreau told CBC News

Moreau is asking Air Transat for a partial refund over her encounter with the spider. 

The tarantula that climbed her leg was one of two on the Montreal-bound Air Transat flight from Punta Cana, Dominican Republic. 

Passengers screamed and stood on their seats after learning they were sharing the cabin with the spiders. 

Julie Roberts, vice-president of Air Transat’s flight attendant union, said flight attendants "did what they could to calm people down." 

"They gave first aid to the person who said that a spider climbed (her) legs," she said. Flight attendants also asked passengers to put on their shoes and cover their ankles. 

Moreau wants the four flight tickets for her family partially reimbursed by Air Transat. The incident left her scratched and her 11-year-old daughter suffering from shock, she said. 

According to Moreau, after she brushed the spider off her leg, it hid under her daughter’s luggage. Her husband came and grabbed it and asked for a bag from the cabin crew to hold the spider. 

"It took a long time from when we screamed to get a bag to put it in," Moreau said. 

While the tarantula that crawled up her leg remained in custody, the other spider continued to roam the plane before being recovered by a federal agent once the plane landed at Montreal’s Trudeau Airport.