Moeblob

From WeeabooDB

A moeblob is defined as a character whose soul contribution to the work in question is to be moe. Moeblobs aren't characters so much as they are mascots, as they add nothing of value to the story being told and typically just sit on the sidelines making random "cute" noises. Moeblobs are not always relegated to a tertiary role within a given show, however.

Think of them as robots; They respond to situations presented within a story based upon their archetype and predefined programming rather than react as a normal, well-written character might. They're predictable, and only present within a given show in order to entice a specific subset of otaku to watch.

Examples

• Saki is an exceptional example because every single character in the show is without question a moeblob.
• Misa from Death Note rarely contributes anything of value besides fanservice.
• Sakura from Fate/Stay Night is a worthless mascot character even in her own route in the game.
• The title character in Kurokami has like an on/off switch. When she fights she's okay but outside of that she's in full on moeblob mode.
• Most of the cast in Clannad has no place in the story outside of their own routes. In the anime, characters like Kotomi come off as blatant moe pandering.
• <Your examples here>