So I built a kraken mini, with help from some of the techniques DMScotty used for his Watcher in the Water build (his version takes a different tentacle approach).  It's constructed primarily of aluminum foil, tissues, and glue, with some Sculpey/Fimo-style polymer clay for the tentacles and eyes.  First the finished product, from above:

Kraken Top View

A few popsicle stick shards for teeth on the front:

Kraken Front view

Side view; the four large tentacles with suckers are detached so they can move about the board to grapple things:

Kraken Side View

First I roughed out the tail shape from aluminum foil and then layered wet tissues over that, slathering them with glue:

Kraken Tail

Then I sculpted a similar front part from the same materials:

Kraken Front Part

Then I made a couple marble-sized eyes and some ridges/lids around them from polymer clay, and glued them in place with E6000; a bit more tissue/glue was used to smooth in the tail with the mouth piece:

Kraken with eyes

And then some smaller mouth tentacles were attached and the main body was ready to paint:

Kraken ready for paint

For the big tentacles, I just shaped the main part from polymer clay.  Then I shaped small balls of clay, squashed them into discs, attached them to the tentacles, and poked them with a dowel to form the suckers.  Then just cure and paint.