As a Treecko: When Jared first picked Ghim, he was disappointed when he rolled Treecko on his D20 rather than Torchic or Mudkip. While Ghim was very good at the start, he quickly became one of Jared's better Pokemon. One of Ghim's biggest successes as a Treecko is defeating Roxanne's Nosepass, which is her ace Pokemon.
As a Grovyle: Once Ghim evolved, he became much better, gaining a needed boost in stats. Especially after the learning of Leaf Blade, Ghim was arguably Jared's best Pokemon on the team at the time. Some of Ghim's biggest successes as a Grovyle include defeating Wattson's Voltorb and Aqua Leader Archie's Sharpedo.
Ghim fell to his fate in the battle against Gym Leader Norman. Ghim hadn't even been used in the battle yet when switched into from Daybo, but he was still one-shot by Norman's Slaking's Retaliate, and it wasn't even a critical hit.