>>50935901Design and personality-wise, without a single doubt.
In gameplay terms sadly not even close but there are at least two things it does better than Clef: Wish and Counter as they both rely on Wiggly's superior HP stat.
Sash counter from Wigglytuff is 966 flat damage, enough to OHKO most dmaxed Pokemon.
Other than that, she can run support/utility moves you wouldn't normally run on Clefable simply because you might want to use Clefable as a setup sweeper in your team instead. Unless the format allows 2 Clefables.