Please please please watch this video. It's really all you ever needed to know.
Thanks for sharing, Barbara!
Please note the bent red US0 dpn, the offending "quarter", and the ever-helpful attempt by a previous genius to keep this problem from happening in the first place. Don't worry, the red US0 dpn was bent before its MacGyver-ish accomplishment tonight. I bent it while making Shorty... SHARK!!'s little brother.

His name is SHARK!!

This one presented an additional challenge, though... he specified not only the colors, but also that he wanted the head/mantle part to look like a yin yang. 
He also wanted the bottom of the tentacles to be a mixture of colors, and my stash generously supplied some matching Cascade Quatro to fit the bill.
I had fun making a different colored octopus with a challenging design feature. The vendor wasn't nearly as excited or impressed as I'd hoped he'd be, but that's why I won't typically knit for cash. I knit for fun. I hope his girlfriend is taking good care of her octopus. He's a cutie.
I have two more octopi in progress in my projects bin. I have dreams of an entire fingering-weight-octopus army. But that's a lot of tentacles. And there are sweet babies in Washington that need some sweaters this year... :)
Ollie lives at my mom's house. She had seen one of his cousins at Great Yarns in Everett, WA, when we visited for Thanksgiving in 2009. So, I searched my stash (I know... were you sitting? Sorry.) and found some Cascade 220 in good complementary colors and got started. The pattern for Ollie is found in Amigurumi Knits by Hansi Singh. The pattern is not difficult, just a little tedious and a mite fiddly, but I love tedious and fiddly, so I loved the pattern. I made a couple sock-yarn-sized Octos, too, and if you clicked the link up there for the blog post about Ollie, you met Celia and Cedric the cephalopods, too.
Jeff performed as a stunt double in the following movies:
(Tommy was born from two different dye lots of the teal yarn. Half of his tentacles are slightly darker than the other half. It's not really noticeable in the pictures, but Tommy prides himself on his tonal qualities.)
Lenny has performed as a stunt double in the following movies:
Eileen is the only female stunt octopus, and has been the Bond Girl stunt double in a tentacle-ful of James Bond movies, including:
(The idea for Bruce's inside out legs was an inspiration from one of my very good friends at sock club - Hi Melinda! - who made her own octopus and inadvertently sewed the legs together inside out. Brilliant!)
Simon has performed stunts in the following movies:
(Tate, oh, sorry... T8 is actually the same colors as the other octopi, but he had his picture taken at a different studio and the lighting was not exactly the same. When you think of T8, imagine a strapping high school lad, his future laid out before him like the red carpet at the Oscars, and... well... T8 doesn't have a resume. He just has a mohawk and a dream.) The following is T8's submission:Dude so like I never been in any movies but I look totally like this dude so I could totally be his stunt double. So I totally sk8board all the time cuz figure sk8ters are LAME!! And I almost gradu8ted in 2008 but I dropped out so I could go to the sk8board CHAMPIONSHIPS in fort Lauderdale and I was totally AWESOME!!! So you should totally let me be this dude’s stunt double cuz I ROCK and stuff.Right. Well.
Ollie is happy to have so many friends, and each stunt octopus has found his or her place in the household. The world is waiting with baited breath for Ollie (and his stunt septuples') adventures!!