of course, not all in one plugin. all you need to do is make creepers spawn a block when they explode and re-texture them (For example, if you make a diamond creeper, give it a diamond skin and make it spawn diamond blocks when it explodes)
here is what i assume: If you have elemental TNT, then creepers also spawn blocks when they explode, and vice versa. all people need to make is an elemental tnt mod with creeper textures.
This is possible by editing the nether reactor somehow! Still hard tho
you could just do what they said, and make it like the elemental TNT, also by editing the nether reactor and making it spawns creepers when used isn't hard IMO.
Can Someone Make a Block-spawning creepers mod?