The Spyder in the Cathedral
In the Introduction, the player character is given a choice between five "new releases".
Instead, the protagonist is later offered one of the five releases from last season, the "old releases", which morph the ordinary way (through leveling up).
Exchange student starting tuxemon
These are the starting tuxemon that the exchange students in Flower City offer to trade with the protagonist. They don't morph, suggesting that some unique process is required to unlock their morphs.