Pets

Pets are a type of NPC found in Terraria. The following can be found on all platforms:
 * Pet Baby Dinosaur
 * Pet Baby Eater of Souls
 * Pet Baby Hornet
 * Pet Baby Penguin
 * Pet Baby Skeletron Head
 * Pet Baby Snowman
 * Pet Baby Truffle
 * Pet Cursed Sapling
 * Pet Eyeball Spring
 * Pet Lizard
 * Pet Parrot
 * Pet Sapling
 * Pet Turtle
 * Pet Squashling
 * Pet Black Kitty

Minions
 * Pet Baby Slime
 * Pet Pygmy
 * Pet Raven

Light giving pets
 * Shadow Orb
 * Fairy
 * Wisp

And the following can only be found on the console version at this stage:
 * Pet Bat
 * Pet Guinea Pig (Also available on Mobile)
 * Pet Slime
 * Pet Werewolf
 * Pet Zombie

The following are only available on their own version at this stage:
 * Pet Android (Android version only)
 * Pet Baby Slime^ (PC version only)
 * Pet Bunny (Collector's Edition only)

As of now, in the PC version of Terraria. You can have one combat pet, one passive pet and one light giving pet out at the same time. I.E. Pygmy, Wisp in a bottle and sapling.