I'm so happy that I found a rare pet drop I wanted to post this so players can discuss where rare pets drops are from bossess so everyone can read it and get a variety of pets. It doesnt have to give a card but if it does, be sure to say which card here are the ones I know of:
Myth treant: gives myth nature's wrath at ancient and does 375 myth damage and stun for 1 round. Oakheart drops this pet.
Icezilla: gives icezilla at ancient does I forget how much ice damage but a little less than stormzilla. Silver Sentinel drops this pet.
Brown Spider: gives giant spider at adult does 195 life damage and puts up a bubble that increases life attacks by 25%. Mooshu pet shop sells this pet.
Life Bat(My recent one ) life bat card at ancient heals 10 for first heal and 30 every round for 3 rounds and heals whole group.
And I'm not sure if this is just a myth but someone told me that plague oni drops life scarab not sure if it gives card and if so which but you can go try it if you want to. The other ones I am sure about because I have had them and used there card so everything up above this is PERFECTLY accurate information. The only card I havent used yet is life bat.