Gamzee first got addicted to sopor slime when he was just a grub, he had accidentally swallowed some when he woke up one morning, and he had been addicted ever since.
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Headcanon #16
Gamzee first got addicted to sopor slime when he was just a grub, he had accidentally swallowed some when he woke up one morning, and he had been addicted ever since.