odoro おどろ

In manga, odoro おどろ are lines drawn on the background of panels that look like an ominous dark smoke, or shadow-tentacles, coming out from the edges of the panel into whatever bizarre thing is in the panel, or into a character who feels all weirded out or angry, pissed off.

They're also called odoro-sen おどろ線, "odoro lines."

Manga: Mob Psycho 100, Mobu Saiko Hyaku モブサイコ１００ (Chapter 55, 知らない)

• Usage
• Examples
• References

Usage

Generally, odoro おどろ are used when something feels eerie, weird, bizarre, odd, unusual, ominous, or when someone feels uneasy, worried, disturbed, angry, annoyed, pissed off, and so on. In some cases, they're used like focus lines.

The term probably comes from the reduplicated i-adjective odoro-odoro-shii おどろおどろしい, meaning "eerie."

Examples

For reference, an example:

Manga: Mahoujin Guruguru 魔法陣グルグル (Chapter 1, ジミナ村)

• Context: Nike ニケ ponders whether to enter an ominous house.
• dooon
  どぉーん
  (sound effect.)
• mahou obaba no ie
  魔法オババの家
  Magic granny's house.
• kaerou ka na...
  帰ろうかな･･･
  [Maybe I should] go home...

References

• オドロ - tonbi.jp