Why did a creeper start to explode and suddenly stop?

I played Minecraft earlier and a creeper expanded next to me but did not explode. It turned white and I thought it was going to explode, but it didn't.

Is this a bug, or just a fluke? I have no idea how or if I caused this, so I'd like to figure it out.

Solution 1:

This happens occasionally, it's usually because the creeper took damage prior to sneaking up on you, and then took subsequent damage when you noticed it, then died instead of going boom. A multitude of things could contribute to this:

• It took fall damage sneaking up on you
• It hit a cactus
• A skeleton or other mob attacked it while trying to hit you
• It might have been a charged creeper (though, you didn't mention a thunderstorm), in which case you got lucky that it didn't explode :)

Sometimes, it's just lag that obfuscates what actually happened, I hit this a few times while trying to get a creeper lined up with a firing skeleton. It's not a bug in any version of vanilla that I know of, but if it happens consistently then you might want to look at mods (if any) that you recently installed.

Be more inclined to blame lag, and a pre-damaged creeper that probably fell to its death or got hit with something before exploding.

Solution 2:

I remember from the days of Minecraft before its single player mode became a server + client running in the background. When you get within a Creeper's trigger radius, it begins to swell and make it's telltale warning sound. If you could get out of that radius before it blew up, it would shrink back down and not blow up.

I believe this mechanic is still in Minecraft, but because of latency and lag it tends to not work. That is, the server tells the client that the creeper is going to blow up rather than the client telling the server. Thus if the player moves out of the trigger radius but it takes too long for the server to get that message, the creeper will still blow up.

In your case, what probably happened was that you got far enough away fast enough that the server got the message before the Creeper detonated.

Solution 3:

Tim Post's answer already sums up most of the possibilities why the Creeper didn't explode.

Another reason could be the fact that there was a cat or ocelot around (maybe a few blocks away). Creepers flee from ocelot and cats (tamed ocelots).