In addition to Gravity's regular pets, which you can find a nice table of by following this link:
http://www.roempire.com/database/?page=monsters&act=pet
heRO has their own custom pets with special taming item!
I will be adding more as time goes. ^_^
Regular Pets
Kraben
Tame: Banana Basket (drops from Kraben)
Eat: Banana Juice
Wild Rose
Tame: Fuzzy Yarn Ball (drops from Wild Rose)
Eat: Salmon (obtainable from Fishing system)
Succubus
Tame: Black Lipstick (drops from Succubus)
Eat: Immortal Heart
Galapago
Tame: Latest Fasion Sunglasses (drops from Galapago)
Eat: Pina Colada (drops from Galapago)
Karakasa
Tame: Golden Geta (drops from Karasaka)
Eat: Mochi (drops from Karasaka)
Ninetail
Tame: Starball (drops from Ninetail)
Eat: Tofu (drops from Ninetail)
Baby Garm
Tame: Snowflake (drops from Baby Garm)
Eat: Nursing Bottle (drops from Baby Garm)
Teddy Bear
Tame: Mjolnir Replica (drops from Teddy Bear)
Eat: Well-Baked Cookies
Waste Stove
Tame: CLR (drops from Waste Stove)
Eat: Coal
Siroma
Tame: Blue Scarf (drops from Siroma)
Eat: Ice Heart
Civil Servant
Tame: Imprint of the Cat King (drops from Civil Servant)
Eat: Catnip (drops from Civil Servant)
Snow Bunny
Tame: Strawberry Pudding (drops from Snow Bunny)
Eat: Songypon (drops from Snow Bunny)
Aliot
Tame: Briefcase (drops from Aliot)
Eat: Burnt Pieces (drops from Aliot/Alicel/Constant)
Lesavka *New*
Tame: Green Fairy Mirroc (drops from Lesavka)
Eat: Calla Lily Flower (drops from Lesavka)
Heroic Pets
Angeling
Tame: Father Benedict Holy Water (quest for light hero!)
Eat: Large Jellopy
Deviling
Tame: Lord Matthew Cursed Water (quest for dark hero!)
Eat: Large Jellopy
Observation/Dame of Sentinel
Obtainable as a result of the custom Thanatos Tower quest (for high allegiance light hero!)
Eat: Topaz
Baroness of Retribution
Obtainable as a result of the custom Thanatos Tower quest (for high allegiance dark hero!)
Eat: Ruby
Lady Solace
Obtainable as a result of the custom Thanatos Tower quest (for low allegiance or neutral heroes.)
Eat: Blue Gemstone
Note: For now, none of the pets have any cute-pet-armor, I can't seem to make it work yet, I'll keep working on it. Until then, none of the pet can have any "skills", some of them are looter however.