That ball of blue hat fluff was Rayon - named, as all dust bunnies are at first after the thread of which it was made.

On animation: From eew to aww. Part 1 - Dust bunnies are going to need a makeover

Sadly dust bunnies are unprepossessing items in the harsh light of day. For their animated debut they’ll need as much romancing and glamourising as modern technology allows.

That simple sketch is how a dust bunny first manifested in my imagination - as an as-yet-still-insignificant ball of blue hat fluff, blue as the sky outside, cast adrift into mid-air and the arms of gravity.
My friend John kindly sketched the same scene up for me.

Rayon falls from hat

However real dust bunnies are scruffy oiks. Look at them, poorly groomed and coarsely entangled.

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It’s going to take some radical character development to glam them up for the big screen.
There's a lot to consider; what will dust bunnies look like- their texture, their colours, their degree of scruffiness and all those wayward threads.
How will they move around the house? The Wind will tell us that though. On animation: The dance of the dust bunnies
But the big question is how to incorporate their emotional expressions - physically they can wave their thready arms easily enough but they'll need a face of sorts.
The Lego movies had a clever solution for that, they just animated the mini-figs painted faces.
It's probably possible to create photorealistic facial expressions for the dust bunnies using motion capture but that incurs personhours and computational expenses, another factor to consider.
We take many of our communication cues from eyes so that'll be the tricky bit for the character designers. Not my job though so tra la la la, let's press on.

The writer gets his big crayons out

Here’s some early character studies I did - much as Leonardo Da Vinci did for his subjects. In art circles this is technically known as scribbling but it’s an attempt to capture the random, ungroomed anatomy of a dust bunny’s entangled threads and fibres. Got the colour for Rayon though, needs to be blue so blue he is.

Eyeless and armlessrayon on blue
Oil pastels give Rayon a lovely intense blue but he's eyeless and armless
Big rayon on blue
The first vestiges of sentience and expression - baffled and bewildered as per usual
Tiny rayon in pencil
"The Wind picked up Rayon and sent him skittering across the floor, skippetty, skip skip."

But many and various are the dust bunnies Rayon encounters. Knickers is the first domestic dust bunny he meets, the Queen of the dust bunnies. They collide in a static electrical clinch.

Knockers sketches
Sketches of Knickers. She became Queen of the dust bunnies when I put a bit of my frilly knickers on her head as a crown

She gave up struggling against Rayon’s persistent clinging. ‘Knickers.’
‘Well, I’m not too pleased about this myself.’
‘No. Me, you fuzzball. Knickers.’
‘Is a name?’ tried Rayon.
‘Correct. Gusset stitching, pearlescent lacey trim and elastic. You?’
‘Rayon. Ex-hat. Treated cellulose. Recently entangled. Pleased to meet you.’

Knickers takes Rayon to the dim gloom under the bed where she introduces Rayon to the Biddies, entangled as they are from a bit o' this and bit o' that. Biddies are drab on the outside and drab on the inside. "They're dreadful materialists." explains Knickers.

Greyblackbiddy copy
Seen one Biddy, seen all. Moving on then.

Meet Yarn from the attic. He's got an interesting story to tell Rayon

Yarn in pastel sketch
Yarn is the densest, most enigmatic richly entangled dust bunny in the house. I always saw Yarn as magnificently chromatic when sunlight penetrated the shadows of the attic, glowing with exotic colours and threads.
Yarn in attic 2
Tapestry
'Wherever did all Yarn’s threads come from? wondered Knickers.' I stole them from stuff like this.

2D or not 2D? The great leap sideways

Lion king 9419
When I first saw the wee cub in the Lion King 2 trailer in glorious CGI, I thought it was a documentary.
Animation can be much,  simpler and still work perfectly. This is a frame from Samurai Jack versus the Shinobi shadow warrior by Genndy Tartakovsky.
2 samurai jack shinobi
Scruffy and approximate works too. Here's Roobarb from Roobarb and Custard.
5 Roobarb
Written by George Calveley and animated by Bob Godfrey

So Rayon and the dust bunnies could be animated by ye olde-fashioned cel animation. I wonder what Rayon would think of that?

Rayon and hippo
"You dancing?". "You asking?".

But yes, Rayon will probably look real as real can be, all photorealistically astonishing. I do like this impromptu blendo of of photo and graphic styles though.
But before we start throwing the logs into the boilers to spark up the
supercomputer rendering farm, let's take a look at the poor man's 3D
next - discount store dust bunnies.