Episode I: Chomper and Ruby Settle in the Great Valley
Though their coming to the Great Valley was told in a flashback in the Season 2 episode Sharptooth Family Reunion, it didn't really mention what happened afterward. This helps fill that gap.
Episode II: Guido, Chomper, and Tricia
Guido is assigned to babysit Tricia. While doing so, he meets Chomper. How will the Glider react to the Strongbiter? (This incident was referenced in the episode Hermit of Black Rock.)
Episode III: Bron, Shorty, and Chomper
Bron and Shorty come to the Great Valley to visit and see that Littlefoot has befriended Chomper, a Sharptooth. How will Bron react? (Note, in Big Longneck Test, it seemed that Bron and Shorty had already met Chomper.)
Episode IV: Shorty's Big Longneck Test
While I had thought of perhaps referencing this in LBT XVI: The Lonely Longneck, showing it in more detail here might not be a bad idea.
Episode V: Chomper and Ruby During Journey of the Brave
This really isn't Season 1, but I felt that they showed too little of Chomper and Ruby in that movie and that we were jipped as an audience, so I decided to show what they were doing during the movie in more detail.