After reading the book: The mistakes we make. It game both pets an alchemy bonus. I looked around on the pet page, and i cannot find where it listed that bonus, though. Also, what other books that you know of, give out bonuses like that? Not specifically alchemy. Or is it random?

With every 16th book you read your pet you get an Alchemy point. They are used to equip scrolls in the Battle Colosseum.

You get one alchemy point by each sixteen books read.

Ah... Alright. Thank you.