From a distance, dormant dragon engines can be mistaken for harmless statues. By the time you get close enough to spot the scorch marks, it's too late.

Dominaria Remastered

Dragon Engine

{2}: Dragon Engine gets +1/+0 until end of turn.

Those who believed the city of Kroog would never fall to Mishra's forces severely underestimated the might of his war machines.

Masters Edition IV

Masters Edition

"How is it the legged engines seem so much more alive than their wheeled counterparts? Simply, they were born, not made."
—Mishra

Classic Sixth Edition

o2: Dragon Engine gets +1/+0 until end of turn.