Echelon

Echelon is a 2016 megawad by Sverre André Kvernmo (Cranium), built for the ZDoom source port. It consists of 30 mostly very short and small maps, with a heavy cinematic flair thanks to some scripting effects and storyline texts after each map (meant to be a retelling of the story of Doom II), alongside many new graphics and even three new enemy types.

Custom monsters
The WAD includes three new enemies defined through DECORATE:
 * Viper:A snake humanoid enemy that fires a flurry of medium-speed projectiles against the player. It has only 120 health but it explodes violently when killed, damaging anything nearby. (thing type 22415).
 * Clusterfiend:A floating blue enemy with a massive jaw that spits large plasma projectiles at the player, which on impact create a smaller projectile. It has 225 hit points and releases between 3 and 5 health bonuses upon death.(type 24369).
 * Midasfiend:Similar to the clusterfiend, but yellow in coloration and firing a more dangerous projectile which splits into four smaller ones upon impact. It has 450 hit points and releases between 3 and 5 armor bonuses upon death. (type 24370).