A Stealthy Challenge! (Japanese: 忍法対決!ゲコガシラ対ガメノデス!!Ninja Arts Showdown! Gekogahshier VS Gamenodes!!) is the 52nd episode of the XY series, and the 851st episode of the Pokémon anime. It first aired in Japan on December 11, 2014 and in the United States on February 28, 2015.
Spoiler warning: this article may contain major plot or ending details.
Instead of Professor Oak's Pokémon Holo Caster, Professor Oak announced a new trailer for the new Pokémon 18th movie about Primal Groudon, Primal Kyogre and Mega Rayquaza.
In one scene, Greninja's mouth is colored blue instead of cream.
In one scene, the pupil in Greninja's eyes are colored black instead of white.
When Clemont and Serena were falling, Clemont was to the left while Serena was to the right. When Greninja saved Serena and Froakie saved Clemont, Clemont and Serena swapped places despite Greninja's tongue and Froakie's Frubbles not crossing each other's paths.
When Barbaracle used Mud-Slap, it shot up two streams of mud off the ground, yet Pikachu, Greninja, and Froakie each got hit in the face by a different stream of mud, meaning a third stream appeared out of nowhere to hit Froakie.
Greninja's face error
Greninja's pupils error
Barbaracle's finger error
Dub edits
In the dub, Clemont states that Greninja was poisoned, not badly poisoned.