A bubble gum bomb is an invention of Velma Dinkley. It is triggered by a detonator, and causes anyone near it to be caught in a sticky, gummy mess when activated.
It resembles pink bubble gum.
A Pup Named Scooby-Doo
Dr. Croaker was stealing first edition Commander Cool comic books, so Velma planted a bubble gum bomb inside a phony comic in order to trap him. Croaker took the bait, and he ended up caught in a pile of sticky, pink gum.