It makes for a spooky photo on a foggy day. You're looking at an inflatable jellyfish in a 4 storey atrium called the Queen's Lantern. Located inside the front entrance of the Canadian Museum of Nature, this glass structure was unveiled in 2010 and was meant to replace the original stone tower, removed in 1915-1916 due to unstable soil that wouldn't support its weight.
The Queen's Lantern also improved traffic flow in the building. A beautiful staircase leads from the foyer to the first floor but the floors above were poorly serviced.
The inflatable jellyfish replaced an inflatable whale. Incidentally, it is meant to resemble a species of jellyfish, Pelagia noctiluca, or the mauve stinger. Most photos show it from the outside at night with the much loved jellyfish bathed in a lantern like glow.
References
Backgrounder - The Queen's Lantern
Images
Photo from the iPad of 
@kansuze