- Echo!Frisk (Echotale)
- Gaster!Sans may be the first and only one to appear on both AUs.
- Gaster!Sans tends to be seductive, and likes to toy with Echo!Frisk, doing things the usual Sans-es would do.
- He smokes, but only does it because he thinks it's cool.
- He's an alcoholic, drunk most of the time.
- He has no confirmed backstory.
- Sometimes he is drawn with a chain belt, sometimes not. Whether that is the creator's canon ￼is unclear.
- His name is occasionally shortened to "G!Sans" or just "G".