I enjoy the jiggly matchup now that I realize that dk is a better puff. Both play a bair neutral, but DK has many more advantages imo.
DK can chaingrab puff at low % and get good follow ups on bad DI, along with guaranteed punches at medium % off grab.
DK weighs over twice what jiggly weighs.
DK has a punch, while jiggly has a rest. Punch is a lot more practical, especially since most puffs will camp you and you get free punches. A random punch in neutral is super hard to punish, and it usually is a death if it connects.
DK can kill with uairs at fairly low% due to her weight, while jiggly will not be able to kill DK off the top.
DK can cc dsmash kill jiggly at 70% on most stages.
DK can upB oos shield mixups, and kill at fairly low %
Jiggly can just bair wall, but if she messes up even a bit, DK can capitalize much more than I would say jiggly can.