item_grubnugget
item_grubnugget is a point entity available in 
Half-Life 2: Episode Two. It's a small yellow chunk that falls out of antlion grubs when they get squashed. When player is not on full health, it heals the player by 1 health point when they come close to it. If player has full health, player can pick it up and throw it just like a physics object but it's fragile and will break easily.
