I'd like to add some bwolves coming from someone who's been trying to complete the collection aha.
You have the 3 pps bwolves from 2012 halloween which are EXTREMELY HARD to trade for
All 2012 Halloween (Very Rare)
These are the two trades for the pps bwolves;
Princess/Cowboy and
Witch.I was actually kinda lucky with those trades because the demand for these 3 is insane, I've been seeing some people give them a worth of upwards 0.25ma/0.5ma.
The best way to get these guys is to offsite trade which is a bit sad aha.
Next one is this guy
2016 February (Rare)
Most of the time when you trade for this bwolf your trades get shot down so quickly. I had so many people edit my trades so I would be offering minimum 1x 09 rare for this guy, I was lucky I found someone that let me buy it off them with c$ but even then it was roughly ~30C$ which would've been worth around a 2010/2011 before the rarity update.
I can back up everyone talking about both the pps dog coocoon and the pps see-through one; they are both a pain to achieve.
This guy was much easier to find and trade for than the other one; Normally I see people trade a couple rares older for this pet (e.g 4x 2014 rares or 1x 2009 rare) but I have seen the couple crazy trades like 0.25ma-0.5ma.
Can agree that people do worth this guy to 0.5ma, I on the otherhand on traded an 09 vr
Seen here.
Some other hard to find/valuable bwolves include this dude;
2013 September (Very Rare)
Which most people to try get a couple older/rarer pets for it but nothing too crazy that it reaches the list territory.
The entire set of bwolves from the beach event in 2012.
Linked the first pageConsisting of 8x rares and 2x very rares.
There's more but I don't want to make the post too long aha
-EDIT
Adding this bwolf in because it still has a bit of demand
2019 Fae Event (Rare)
What I had to trade to get it