SVG Goo

It's a well known computer graphics technique that blobby shapes can be drawn as the isosurface of a scalar field.

It's actually possible to create a similar effect using SVG filters:

The field is created using Gaussian-blurred circles. Where these soft edges overlap, the alpha channels are composited and this creates the necking effect which is key to blobby shapes like this.

The thresholding is done using a high-contrast filter on the alpha channel. The specular highlight was added just to emphasise the gooey, ketchup-y effect.

If you have a copy of Inkscape, it's fun to play with dragging the circles. Feel free to download the SVG.