This kinda reminds me of War with the Newts from Karel Čapek: https://en.wikipedia.org/wiki/War_with_the_Newts https://en.wikipedia.org/wiki/War_with_the_Newts

This kinda reminds me of War with the Newts from Karel Čapek: https://en.wikipedia.org/wiki/War_with_the_Newts https://en.wikipedia.org/wiki/War_with_the_Newts "War with the Newts (Válka s Mloky in the original Czech), also translated as Salamander Wars, is a 1936 satirical science fiction novel by Czech author Karel Čapek. It concerns the discovery in the Pacific of a sea-dwelling race, an intelligent breed of newts, who are initially enslaved and exploited. They acquire human knowledge and rebel, leading to a global war for supremacy." The Newts use explosives to demolish land, creating more of the shallow sea they prefer to live in & they also use poisonous gases and other weapons against the humans. And all the time, there are at least some humans who sell them explosives, chemicals or arms to make a quick buck. The only thing that saves the remainders of humanity in the end is that the Newts eventually start fighting each other and wipe themselves out...