now that deathstalker and forest scorpion came (or coming?) out i feel scorpio needs a big boost some how, especially if you want it a rare, because if you compare it to forest scorpion:
Scorpion- 1l2 1 poison for successful attack, 3

Scorpio- 3l1 1 poison for successful attack and infection, 5
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so they're very similar and you want scorpio rare? just make a few changes like more health and or attack