Anime/O

On

 * One Piece: The world of One Piece is full of humanoid beings of various shapes and sizes. Sizes range from small dwarves to very large Giants like Sanjuan Wolf. Although most of the known huge beings are male, there are still a handful of tall females. Some like Shirahoshi and Big Mom are very large despite the fact they aren’t from the Giant race. Semi-giantesses include females of the Snakeneck and Longleg tribes.
 * One-Punch Man: A parodic series about a superhero who suffers because he defeats all his opponents in a single punch.

Or

 * Oriental Child Prodigy - EP01: The original name of this Indonesian anime is "东方神娃". A brief battle between an Asian woman and two sea beast is ended when the women grows in size and she defeats those beasts.

Ou

 * Ouran Highschool Host Club - EP13: "Haruhi in Wonderland". Alice in Wonderland related episode, where Haruhi has the role of Alice.

Ov

 * Over Drive Girl 1/6: Similar to Frame Arms Girl. Little humanid female dolls have "life" and interacts with humans.