Here's a couple ideas I haven't put else where yet.

Obsidian with more of Fire Obsidian texture, changing it up so it has a bit of random loot drop with a chance of 1-3 Iron (4%) or Gold blocks (2%), 6-12 Redstone dust (1%) or Lapis lazuli (0.5%), and small chance of diamond (0.3%) or emerald (0.1%) and if you get really crazy some form of small diamond and emerald fragments that act much like nuggets for metal ores (doubling their loot odds to balance).

A Scarecrow that acts like a dummy lure for all but zombies, can't attack the mobs, and has some health (half of an iron golem) Recipe is 4 logs in a T and a carved pumpkin.

Please