In the costume's card graphic, Green Thumb seems to carry a gardening shovel, which is never seen in the costume's video presentation when unlocked.
It was originally offered in the first festival in premium Tier 1. Originally, the costume required 60 cards to unlock, but the game vendors changed it to 50 very soon after the v.7.9.0 update was released. Players had complained that the 50 cards that were offered in the premium tier were not enough to unlock the costume. To earn more cards, players needed to open premium crates after reaching tier 50 and later on, more cards were available during Zen Garden special mission.
The costume's original description used to be "Each second counts 300%-370% more while using the Banana Splitter and it was very similar to DJ. However, in 8.0.0 version on August 4, 2021 it changed to seconds without the use of the said power-up, decreasing the percentage by a lot.