This resource pack shows, which blocks could be hazardous to you by adding a skull overlay (glowing effect icon). It works with any resource pack (set this one as topmost), but you do need Fabulously Optimized, Continuity or OptiFine.

This pack works on

• TNT
• Magma Block
• Respawn Anchor (Overworld and End)
• Powder Snow
• Trapped Chest (fixed textures)
  
• Sweet Berry Bush (without berries)
• Big Dripleaf (inactive top layer)
• Pointed Dripstone (top/bottom tips)
• Wither Rose
• Cactus
• Tripwire (hooked)
• Sculk Sensor (inactive)
• Sculk Shrieker (summonable)

Demonstrated with default and Faithful 64x but works with any resource pack.

FAQ:

• Q: It doesn't work at all!
  • A: You need Fabulously Optimized, Continuity or OptiFine. Make sure it is set as the topmost resource pack. It may not work if any other resource pack changes the block/item models.
• Q: I don't see skulls, I see something else!
  • A: Your resource pack creator has decided to change it then ¯\_(ツ)_/¯
• Q: Some blocks are still not supported!
  • A: Yes, I skipped some blocks to prevent making the worlds too ugly. These include: (soul) fire, lava, (soul) campfire, End Crystal, TNT minecart, beds (for Nether, End), pressure plates and buttons.
• Q: What about the ores?
  • A: Check out Items on Ores.
• Q: What about some other blocks?
  • A: Check out Items on Blocks.
• Q: I want to know about infested blocks!
  • A: Check my profile.
• Q: Please backport to...
  • A: Nah.
• Q: Bedrock support?
  • A: No, I don't think the block models work the same there...