Fun Fact - In the extras for the movie, they mention that making Hank nearly broke their rendering software. When they tried to render Hank with eight tentacles, the software couldn't handle it. Therefore, they lopped off a tentacle. That's what drove Hank to be a "septapus."
Not-so-fun-fact - DO NOT WATCH THIS MOVIE HUNG OVER. My wife and I put this on for our kids a few days after it came out on blu ray after we had a little too much to drink at a holiday party. Let me tell you, no pain killer in the world is a match for Ty Burrell's "sound effect" for echo location in this movie. Every time he did it (which is a lot), my head felt like a resonating wine glass.