sometime during the first year around the 16th of Spring, go to the forest where you normally can fish for the king of The lake. you will find an egg.
Approach and try to pick it up. text will appear stating something similar to "if you don't take it, it will be eaten by wild animals". select "yes" and take the egg. after about a year it will hatch. once again, text will appear.
Your partner will say "oh..??? an egg hatched... how cute! he thinks you're his mom... Oh! why don't we name him 'pak' ?! yes! he's a pak!".
Pak lets you talk to animals on the farm and perhaps makes all of your crops (tomatoes, corn, and watermelon) ripe for harvest on his date of birth.