- Some of the monsters: Gan Q, Zetton, Alien Baltan, Dada, the various Assimilation Plot monsters (Solitura, Alien Illudo, etc.), and every monster in Ultraman Nexus (particularly Nosferu, Kutuura, and Banpira).
- Ohhhh yes. Ultraman Tiga, Ultraman Cosmos, Ultraman Ace, and Ultraman Gaia seemed to have particularly nasty kaiju or villains, like Gatanozoa, Magnia, Chaos Header, Yapool, and Fake Agul (Algyuros),whose creepy smile was something that scarred kids' memories for a very, very long time.
- 100 Union Kaiju Beryudora, Ultraman Belial's One-Winged Angel form in Mega Monster Battle: Ultra Galaxy Legends. Not only is the thing downright demonic in nature, it's body is made up of scores of complete and LIVING KAIJU, each of which is moving and roaring, grabbing at opponents that are attacking.
Nightmare Fuel / Ultra Series
Sci-Fi Horror series Ultra Q, but just because it's moved on to superheroes doesn't mean it's no longer capable of being terrifying for both kids and adults alike.