Narbles was a Meowth that Jared caught at Level 10. Narbles was caught and had her fate met in the episode, Diglett's Cave. Despite her short appearance on Jared's team, she managed to level up three times from wild and trainer (assist) battles, until she entered the Diglett's Cave.
There, Jared made the grave mistake of keeping Narbles as a starting Pokemon, with a wild Diglett's Arena Trap preventing him from switching to someone else. This led to Jared spamming potions onto Narbles, up until the Diglett landed a critical hit with the move Dig. Jared exclaimed later in the battle that it was his own fault for Narbles' death.