Werewolf: The Apocalypse - Earthblood

In this video guide I will show you how to kill an enemy with an explosive barrel. This will finally be available on your second return to Washington State Forest. You will be tasked to meet up with a teammate, then enter the Endron to the right through the vent. Now you will need to get caught then melee the barrel toward a weaker enemy. This should kill them instantly for the achievement. If not there are a few more areas with barrels, or reload the checkpoint.

You will most likely get this inadvertently either during the dam mission, or any subsequent mission, especially if you aren't playing the long stealth game aside from some sabotage stuff to make your life easier.

The flame barrels are first seen throughout the fighting areas at the dam, and continue to be seen throughout the remainder of the game during story missions. These red barrels are very easy to spot.

They normally take two hits to make explode, but they also have a bit of a time bomb mechanic, where you can "light" the barrel by slashing at it in wolf forme, and after a couple of seconds it will explode. There may be a more advanced strategy to do this, but how I got it the first time was letting some of the basic guards chase me, let them catch up, slash the barrel, and dodge at the last second and make them get caught in the crossfire. But you can also throw enemies into the barrels, you can make THEM trip the little time bomb mechanic they have, or you can just do how I've done since and just horribly mangle them over and over around the barrels and ignitable cars and let Mother Gaia take its course.