Chameleon Skin is also a freebie: it’s a passive ability that grants gain on Stealth Checks. No tactical implication; it just makes the yuan-ti greater at what it now does.
increased ssvaklors also exist, even though https://crithitceramics.com/the-importance-of-setting-in-a-campaign-a-guide-for-yuan-ti-pureblood-monks/