The information added includes Price of each pet, and what Effects the pet has.
Pets are unlocked by raiding the Enemy cafés in the English version of the game. (Not sure if they come directly from raiding the associated enemy café, or from buying the stove that is unlocked from that raiding.)
Since I have the English version of the game and have been raiding for years, I have most or all of the pets unlocked—though I have only bought two types so far; the two paid for with $, not Toxin.
I will add some more pets' information to the Pets page. There's a Cheshire Cat, Great Sphynx of Giza. Looks like those are all that are still missing.