Mr. Kroop is the manager of the bank and not a very nice one. He is also a cat person and has smiley face pens (though they don't usually work). When he realizes that Sam Cortez's parents are unable to make the mortgage payments: $40,000, he is set on making their house belong to the bank. He gives Sam a smiley pen as a consolation. Despite the fact that they have enough time left, he and his workers show up before the deadline, anyway and decide to acquire the house. Papi, Pedro, Delgado, and the puppies decide to retaliate against the human group. Papi pees on the documents that Mr. Kroop needed for the family to sign on. Infuriated from all the stunts the dogs pulled, Mr. Kroop demands that they be evicted by midnight on the same day. He then takes the same pen he gave them the other day.
Later, he is seen outside of the bank as it was being robbed by three crooks talking and exaggerating about the situation. After the dogs capture the robbers, Mr. Kroop comes by the house with the Police Chief and tells them that there is a $250,000 reward for the crooks' capture, which is basically theirs. It becomes more than enough to pay off the mortgage and more, thus allowing Sam's parents to keep their house. He then has a change of heart and gives them a real pen to sign the document to verify it all. The Cortezes and the chief hug him as a sign of joy and gratitude. In the end, all the dogs dogpile on him and keep licking him to show him gratitude as well, thus, making him also a bit of a dog person at last.