Bringing The Farm To Live In Another World by Ming Yu - Chapter 2003: Inspection

Violet skies, a world undergoing massive changes, a deficient moon, interlinking voids…
When the world experienced a cataclysmic event,the majority of living things ceased to exist. Although humanity survived by hiding in the last safe zones, humans had to face mutated dire beasts and colossal source beasts that could break through the space barrier and enter the earth at any second.
Luo Yunyang, a young man who grew up in those calamitous times, obtained an attribute regulator and set out to walk the path of supremacy!

- Description from novelupdates

I've transmigrated to the Honkai World and became the future Herrscher of Ice, Kiana's cousin, Durandal's cousin, Ana Schariac.Hmph, I must become a Valkyrie aboard the Hyperion at all costs to survive!Come join the Ana fan club!Wait! I'm just a fictional character, not your wife!Players, you guys are so peculiar!Ah well, let's embrace the chaos!*****

However, he did not know that he was not raising just a harmless pet, but a biological weapon secretly made by the government… a real monster.

As a former librarian, Rand felt that he had been living an ordinary life, the one that he had reclaimed unconsciously every single day.

Recently, he has been a little upset because the pet fish he accidently brought home to raised seems to have undergo some strange changes

Well, it turned into a merman.

- Description from Novelupdates