Suddenly Harmful Harmless Object

The scenery in games has been known to do awfully strange things. For example, say you're finishing up a sidequest. You've just found all three sacred stones and put them next to the magic fountain. As you walk back to collect your reward, everything seems normal-- ''What the hell! Since when did that harmless bush have spikes?''

The Suddenly Harmful Harmless Object is a monster that is usually part of the scenery, or at least something benign, much like the Wall Master and Chest Monster. It becomes dangerous as soon as a certain condition is met. Usually, they become harmless again the moment the condition is no longer met, although it's sometimes permanent.

These can be used for several purposes. Sometimes, they're used to prevent backtracking, to make an easy area more dangerous, or to make subsequent playthroughs of the game more difficult.

The Event Flag may be triggered by an Artefact of Doom.

Compare Empty Room Until the Trap.

A staple of Platform Hell. See Chest Monster for when there's no Event Flag. See also Ninja Prop for other examples of suddenly harmful harmless objects.


 * Blobbz Online has Nightmare Mode, where trees and birds, which are harmless in normal mode, can kill you.
 * Eversion has this with the flowers. The flowers remain more or less part of the background until 5-6, where they become spiky and are instadeath.
 * The water may also count. in 4-5 and later, the famous demonic hands appear from the previously much less terrifying water.
 * Those strange rocks from Level 5 become harmful in X-7, and then become actual demons in X-8.
 * Phantos from Super Mario Bros 2. They look pretty much like background scenery until you pick up a key... and then they chase you through the entire level until you use said key on a door. There is also the final hawk-head doorway, which attacks your character when you pick up the crystal that otherwise opens its earlier counterparts in the game.
 * Remember those statues that you've been passing by the entire time in that tower in The Legend of Zelda Wind Waker? Well, they turn into massive, spiked harbingers of death at times.
 * Dead zombies in the R Emake of Resident Evil. If they're left unattended without burning the corpses or killing them by decapitating them (for some reason you can't spend a few minutes doing it with the combat knife) they come back as "crimson heads". Not to mention pretty much any corpse could potentially "wake up" if the right plot event occurs.
 * There's the sun in two levels of Super Mario Bros 3. First you think "Why the heck does the sun have a FACE?" Then it tries to kill you.
 * In Donkey Kong Country Returns, on Sunset Shores, the player is given a chance to enjoy the scenery before the Difficulty Spike. Or at least it seems like it, until bushes uproot themselves & chase after you.
 * In Puzzle Quest 2, some gameboards have solid 'bricks' that cannot be moved or interact with anything. All they do is get in the way a bit. Perfectly harmless. However, some enemies (specifically, most Undead enemies) can use a move called 'Wake The Dead' that causes a random 'brick' to turn into a lethal 5 Skull - without ending their turn. The move is cheap, too, so you can easily end up in a situation where the enemy uses it three times in rapid succession, turning a harmless wall into a heavyweight 15-base-damage attack.
 * The various defunct robots in the Wrecked Ship segment of Super Metroid come to life and attack your character when the power come back up.
 * You know those Chozo statues that Samus gets stuff from? Two of them try to kill you at different points in the game.
 * Cave Story has sixteen sky dragon eggs in the Egg Corridor. These appear normally (and are completely harmless) before you go to the Labyrinth. After you complete the Core and the Waterway, and regain access to the Egg Corridor, all the eggs have hatched, and most of the survivors are now dangerous zombie dragons.
 * In Sector 2 (TRO) of Metroid Fusion, all the larvae crawling around the place retreat to cocoons and become harmless after you obtain the high-jump boots. When you revisit the level later after the reactor core has gone offline, you'll find that all the cocoons have popped and released dangerous mutant insects.
 * Tower of Heaven eventually does this with the living things due to its book of laws.
 * Shivers has evil spirits known as the Ixupi, which hide in different materials. Every time you enter a room, it's possible that an Ixupi could be lurking there. One minute, you're looking at a pile of ashes; the next, a monster jumps out of it and bites you.
 * The Flaming Sword in Level 12 of Prince of Persia 2: The Shadow and the Flame.
 * Both Dragon Age games have statues and suits of armor coming to life sometimes to attack the party.
 * Ys has a chest in Darm Tower surrounded by statues that become Demonic Spiders once you take the treasure.
 * I Wanna Be the Guy, being a Platform Hell, is chock full of these. Killer apples fall down, up, and home in on you. Stars fall out of the background. Clouds shoot lightning. The moon gets dropped on you three times. A spike pit turns into an Advancing Wall of Doom. Near the end, a Save Point attacks you. And so on.