Looks like Titanfall will include monsters of the large variety, an art book reveals.
Posted on IGN, The Art of Titanfall book shows new details on game's weapons, maps, storyline, and monsters. According to the article, monsters "will walk or fly around levels harmlessly until people interfere. Others will attack when you just stare at them."
This confirms that the creatures will have a presence during in-game combat, joining AI-controlled Grunts and Spectres on the battlefield.
Similarly, a post on NeoGaf alleges developer Respawn Entertainment confirmed that the Leviathan monsters (one which appears in an advertisement for the game on the right) will be present, but will not enter the maps.
The artbook also lists several Titanfall map names that were recently dug up by data miners, confirming their presence in the game. Titanfall launches on March 11 for the Xbox One and PC in North America. For more information, check out GameSpot's The Next Big Game Titanfall feature.