Alien- Gunfire Resistance

This time when they drew near the tattoo shop they heard a loud crash, followed by a scream of terror. The three guards drew their 9mms and started running toward the shop’s entrance.
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There was no way to tell which of them started firing first. Maybe it was him, maybe not. When they began firing at the creature, the thing whirled away to reveal a huge mass of pustules covering the entire back of its body—neck, shoulders, arms, legs… Bullets slammed into its grotesque hide, causing the pustules to explode. A thick black substance jetted toward the three guards, splattering their faces, hands, and coveralls. The goo burned like fire wherever it landed, and all three of them howled with pain.
Oralia and Paolo’s hands had been hit, and they dropped their weapons as their flesh bubbled and sizzled. Saul’s hands had only been struck by small droplets, and while they hurt like hell, he managed to keep hold of his gun. Unfortunately, the left side of his face—from the crown of his head down to his chin—was slathered with the creature’s acidic fluid, and he experienced a pain so intense it wiped away all thought, all awareness of self, leaving only agony.

Prototype, Chapter 14