Whenever they latch onto the ledge using upB or forwardB. They can reduce it by using aerials, but if they were to airdodge onto the stage, then they suffer about 30 frames. There's other characters that have it too like:
Luigi
Mario
Pikachu (2nd qac)
Falcon
Ganon
Squirtle
Charizard
I can't remember the others though.
Luigi
Mario
Pikachu (2nd qac)
Falcon
Ganon
Squirtle
Charizard
I can't remember the others though.