MCU: 10 Fascinating Facts Behind Guardians Of The Galaxy Vol. 2 (2017)
8. Baby Groot Almost Didn't Appear (And Isn't Just Adult Groot Reborn)
Though Guardians 2's biggest detractors point towards Baby Groot as being one of the biggest examples of Marvel's desire to sell toys as much as make movies, it turns out including the character was actually a risky creative choice.
When speaking about the decision to include a younger Groot, Gunn mentioned how he went back and forth on the character's age, at one point intending him to be fully grown and essentially the same as the original in age. He initially didn't think Marvel would go for this baby version, as adult Groot was one of the first movie's most popular characters.
Perhaps even more interestingly, long after the movie came out, the director clarified that Baby Groot was actually a brand new character, and not just a reformation of the one which died in Guardians 1. He stated that hero in the first film is dead, and this new incarnation is his offspring.