Word Hunt is an activity that players can complete daily to earn rewards. During a run you might come across some green letters — collect those and it will spell out the current day's word. Once you get all the letters you'll receive a reward!
This is a challenge you'll want to do every day as the reward is better when played consecutively. For the first two days you will get a Mystery Box, on Day 3 and Day 4 you'll get some Coins. . . but from Day 5 and onwards you'll receive a Super Mystery Box for every completed Word Hunt!
Please note if you forget to do a Word Hunt or happen not to complete a word fully one day that your 'Day' count will restart — in other words, you may be receiving a Super Mystery Box every day (5+ Days) but once you miss a day you'll have to build yourself up to that reward again.
You can view your Word Hunt by tapping on the Season Hunt icon (the meter on the upper left side of the screen) and tapping the 'Word Hunt' tab.