/bamf/ 1. [Old X-Men comics] Notional sound made by a person
or object teleporting in or out of the hearer's vicinity.
Often used in virtual reality (especially MUD) electronic
fora when a character wishes to make a dramatic entrance or
exit.
2. The sound of magical transformation, used in virtual
reality fora.
[Jargon File]
Wikipedia
Bamf
Bamf , originally Bampf, is an onomatopoeic term originating in comic books published by Marvel Comics, in particular those featuring the superhero Nightcrawler of the X-Men. The term is derived from the sound Nightcrawler makes when teleporting.