Calico's 2 allows her to get multiple instances of the Spirit Snatch buff

[steventheeven3]

If you hit spirit snatch with calico 2 on multiple enemies you get the bonus multiple times, additively, only works if you don't already have the buff.

 

[steventheeven3]

Tested further and it's the same for Bepop 1 and Viscous 3

 

[steventheeven3]

Ok yeah, it also works with a regular melee if you hit multiple enemies at the same time, doesn't really matter what character you are.

Sorry for the confusion.