Help trying to achieve a particular effect

Hey guys,

I'm trying to achieve a particular effect and I'm not sure how.. I was hoping someone might know how!

I have a shape, which I'll refer to as a blob, and I want the edges to wobble slightly.. so imagine it's a blob that's alive and kinda ripples.. It's hard to describe, but hopefully you can understand what I mean.

The only thing I can find on Google is people having 2 blobs interact with eachother, which is not what I want.

Thanks in advance!