0388 Grotle

Razor Leaf is the preferred fast move due to STAB. While it deals significant damage, it also has the worst energy generation in the game. 

Body Slam is all Grotle really needs, or can afford. Due to poor energy gains, this is the main (and likely only) charge move Grotle will ever use due to its 35 energy cost and neutral coverage. If 10k Stardust isn't a problem, unlocking Energy Ball would likely be more viable than Solar Beam due to lesser energy demands. 

Bite is generally an inferior move due to a lack of STAB and also worse damage output stat-wise, but an off-typing can catch opponents by surprise in certain formats. 

Grotle is a niche pick for Great League, featuring decently well-rounded stats, a mono-Grass typing, and a somewhat lackluster moveset. The diverse options of Grass-type candidates generally makes it difficult to stand out among them, which makes Grotle the underdog of the bunch. Where Grotle stands out is in its unique moveset which mostly just emphasizes neutral Body Spam. Due to poor energy gains, Grotle can't actually utilize its charge moves as much as it would like to, which leaves a lot to be desired since Energy Ball and Solar Beam are mostly redundant options. Overall a niche pick with loses against many other Grass-types, and while access to neutral Body Slam is generally a good thing, slow energy to back it up is unfortunate. 

With a max CP of 1890, Grotle lacks adequate stats to perform well in Ultra League. While it can beat most Water-types quite easily, losses against Lapras and most Pokemon in the Giratina-centered meta makes it a poor choice. 

Fun fact: Grotle can actually beat Kyogre if given a shield. But you should probably evolve it if you're considering Master League.