Chris's motivation through the episode is to procure a special type of cereal for Beth, in celebration of the first time Beth ever jinxed him until he got her that cereal. Danny mocks this, believing Beth would never even remember such an obscure moment. The end of the episode reveals she does remember, and is touched by Chris's gift.
Chris and Wallow's presents from their parents.
Beth going off to spend the night with her horse at the end of the episode and her Paralyized Horse talking about how much he cares about her in his closing monologue.
Speaking of which, the shot of Wallow cuddled up with all his various pets.
The Paralyzed Horse throughout "Aeon Worm." The moment he realizes he and Beth are in the See-Through Zone, his first instinct is to get Beth out of there for fear he cannot protect her. Of course, by the end of the episode, he's protecting her far more than he ever could otherwise.
At the end of the episode, Plum gives Danny all the credit for defeating the Galorian Tear-Sucker.
The reason Danny was going through that pound in the first place: Rescuing the Jelly-Kid.
Beth hugging Chris after returning from the alternate universe where he died.
6 year old Wallow curing and then sleeping cuddled up next to baby catbug
Season of the Worm/Season of the Mitch
Danny's reaction to Wallow getting his arm lobbed off in Part One, as he realizes that his reckless testing of the Falcon sticker pet mod is ultimately to blame.
Danny's emotionally drained after the above screw-up, but seeing Beth in danger gives him the courage to use his wits and stop the ritual. His hugging of her as the episode closes is made all the more sweeter when the initially hesitant Beth hugs him back...with some help from Wallow.
The end of Mitch's character arc as he manages to help free his brethren and make a difference.