Helper pets help you to complete levels. For pets to throw boosters onto the game board, you have to collect gems of a particular color. As soon as the bar of the pet's ability is filled, they will share boosters with you. There are four pets in the game:
the black cat, which loves yellow gems and throws the lightning booster onto the game board
Winston the dog, who loves blue gems and throws the star booster onto the game board
Polly the parrot, who loves red gems and throws the bomb booster onto the game board
Horatio the monkey, who loves green gems and throws fireworks onto the game board