December 18th: What is this pet? How much is this pet worth?

[Ervalia]

Any idea what these three little guys are?
Any help is appreciated

[XxDipstick]

Could I get some help with these?

That horse is '09 August! All the outcomes are very rare
archive/2009/August/Draft%20Horse

[soccerali9]

Could I get some help with these? :)

That horse is '09 August! All the outcomes are very rare
archive/2009/August/Draft%20Horse

The other is Nov 2010 staff litter, all rares (slightly higher demand than normal because its a staff pet)

[Colorfulcat]

Any idea what these three little guys are?
Any help is appreciated

The bunny is from Easter 2013 I believe!
Edit:
The puppy is from March 2009

[bark]

I can't find them on the list...

1.) Is the purple toxic Nick pet, which is one of the valuable Nick pets! It's from CS birthday 2009
2.) The dog has a chance of growing into an evil pps (an ex-list pet) it's from August 2009!
3.) The horse is from Halloween 2012, and doesn't have any special demand and follows the 3 month rule c:

[XxDipstick]

Any idea what these three little guys are?
Any help is appreciated

The bunny is from Easter 2013 I believe!

That dog is '09 march! There's one very rare outcome, the others are rares.
archive/2009/March/Dog
The butterfly wolf is from '10 July, all rare outcomes.
archive/2010/July/Butterfly%20wolf

[ty6565]

hi, does any one know who this is ?
Adopt virtual pets at Chicken Smoothie!

[madscienced]

Does anybody know what these pets are/how much they're worth?

Adopt virtual pets at Chicken Smoothie!

Adopt virtual pets at Chicken Smoothie!

Adopt virtual pets at Chicken Smoothie!

[XxDipstick]

hi, does any one know who this is ?
Adopt virtual pets at Chicken Smoothie!

'09 March! There's one very rare outcome and one rare outcome.
archive/2009/March/Butterfly%20wolf

[Detective Heart]

Hello, returning player!

These are the two still-growing pets I received from the event.
Jan 2010 -
Feb 2011 -
And this pen has the VR I got as well as a few previous Dec 18th pets.
accounts/viewgroup.php?groupid=7128886&userid=522678

What is the worth of these pets?
How exactly do you judge a pet's worth?

I assumed it was based off a mixture of age, rarity, and demand.
The site takes care of age and rarity for you, but how do you determine demand?
I tried learning from someone about this and there was once a user-made "list" that tried to determine these kinds of things, but it's gone now and was apparently the one thing keeping pets at a steady value. Would it be correct of me to assume that a pet's worth is now based solely on demand? I've been having a hard time trying to understand how even "true date" decade-old pets have so little value. Maybe I'm just too attached to an image I've seen for half my life.

Thanks for any help / explanations!!
Please feel free to DM me since I included a rather lengthy question.