In the finale, Doyle lays three flowers on Van Rook's grave...then picks one of them up and says "two is plenty". This echoed the "lesson" that the notorious cheapskate Van Rook was teaching Doyle back in the very first episode; Doyle knew Van Rook would've wanted it that way. After picking up one of the fowers, he salutes him.
Van Rook's dying words: "Drew, you were the only thing I liked almost as much as money."
While the love Doc and Drew have for Zak is cute enough, the fact that they love the cryptids just as much is adorable. Drew's willing to carry a fully grown Komodo Dragon through the snow on her back, the entire family braves Weird World to save Fisk, and they constantly refer to the trio as "their boys". The Saturdays don't have one son. They have three. And one daughter: Zon.
Throughout an entire episode, Zak vehemenetly denies liking Wadi. Then, Wadi comes right on cue with: "Too bad. You're king of cute." Leaving Zak speechless and with a goofy smile on his face. He no longer denies his mutual romantic feelings for her.
In Zon's A Day in the Limelight episode, we have one of the first moments where Zak displays a sibling-like relationship with Zon. In this case, he develops a Big Brother Instinct towards her when he learns that the Duah is going to kill her when he "marries" her.