Necrotic Blast Ooze

Congratulations, you’re now the proud owner of a cube of necrotic slime sludge that really wants to take someone with it when it goes. Slap it on a wall, a door, or that one NPC who keeps whistling off-key. After 1d4 rounds, the ooze detonates in a glorious hiss of rot and regret. Every creature within 15ft. must make a DC 13 Dex save or take 4d6 necrotic damage and get launched 5 ft. away. Half damage if they actually see it coming. Unattended objects take full damage. Doors don’t survive—they resign, then rot and disintegrate...