Giant Pokémon

Giant Pokémon, while having never played a large part in terms of plot, are nonetheless a reocurring theme in the Pokémon anime. There are several episodes that have a plot that revolve around unusually large Pokémon. Such to the point that it seems to be a rather common mutation for Pokémon to go through.

The earliest introduction to this concept was in "Island of the Giant Pokémon". Although several gigantic Pokémon such as Blastoise, Charizard, and Moltres appear in gigantic forms, they are soon revealed to be humongous robots built for a themepark.

Just a few episodes later, "Tentacool and Tentacruel" showed a Tentacruel large enough to knock down skyscrapers.

Two more episodes appeared back to back featuring giants. In "To Master the Onixpected", Bruno captured a jumbo Onix.

In the very next episode, "The Ancient Puzzle of Pokémopolis" has three giants - Alakazam, Gengar, and Jigglypuff.

The next Giant Pokémon shows up in "The Mystery Menace", in which a Bulbasaur abandoned in the sewers has grown and mutated into gigantic proportions.

Giants don't show up for a while, appearing again in "Gulpin' it Down" when a mysterious invention causes a wild Gulpin and Ash's Treecko to grow to the size of buildings.

Ten episodes later, a story about a Giant Whiscash appears in "Whiscash and Ash.

The last Giant Pokémon was a gigantic Claydol of the episode now known as "Seal the Giant Nendoll!!.