Two giant mechanical creatures are now roaming the streets of Ottawa in a four-day urban theatre performance involving a spider that can reach 20 metres when completely outstretched and a 45-ton half-dragon half-horse that towers 12 metres high.

The France-based performance company La Machine’s Ottawa performance “The Spirit of the Dragon-Horse, with Stolen Wings,” kicked off Thursday night with the awakening of Kumo, a giant spider that had been hovering above Notre-Dame Cathedral.

Tens of thousands of people turned out in the streets of Ottawa to see the massive beasts come to life.

“It seems so real. That’s awesome,” one spectator told CTV Ottawa.

Long Ma, a half-dragon half-horse made that stands 12 metres high and breathes mist out of its nostrils, slumbered on the grounds of Ottawa’s City Hall until he was awakened on Friday morning.

According to the La Machine website, Kumo took refuge in Ottawa after stealing Long Ma’s wings. Long Ma’s goal is to defeat Kumo but first needs to get his wings back.

The urban theatre performance is another part of Canada’s 150 birthday celebrations, according to Guy Laflamme, the director of Ottawa 2017. The goal is to transform the entire Ottawa downtown core into a huge theatrical stage that will include the public as an active participant.

“You will be able to almost touch the machines and feel the breathing of the dragon, the spray coming out of the spider,” Laflamme told CTV Ottawa.

Thousands of people watched the two creatures wake up and take to the streets, posting pictures and video to social media.

Battle on the bridge between Kumo and Long Ma! If you're in Ottawa, don't miss La Machine this weekend. So cool! @ctvottawa pic.twitter.com/bHHt4tfRTg — Matt Skube (@mattskubeCTV) July 29, 2017

As the Sun sets a shadow darkens the sky as Kumo awakens ... #sunset this evening in #Ottawa. #LaMachine pic.twitter.com/SKHxCWIoAS — Nancy (@NancyFromCanada) July 28, 2017

#LongMa, prévenant, baisse la tête pour ne pas se prendre dans le câble #LaMachine #ottawa2017 pic.twitter.com/O63h31jVmw — Compagnie La Machine (@lamachinefr) July 28, 2017

Accompanied by a floating orchestra, Kumo and Long Ma will roam the streets causing rolling street closures throughout the weekend. Roughly 100,000 people are expected to attend the performance.

The French street theatre company was founded in 1999 and is making its North American debut with the standoff between Kumo and Long Ma.

The two creatures will meet on Saturday night at the Supreme Court of Canada before the finale on Sunday night at the Canadian War Museum.