The physical description is
Given the golden fur and tarantula-like description for the thorax and abdomen, I'm ok with the racial bonus. Of course, we also mean dry, yellowish grass even for the lion part, which makes even more sense for me with the tarantula.
Poison damage sounds like Con plus a progressive web effect (or we could make it Con and Dex). At 7HD, we could do 1d6/1d6 Con.
Updated.
Skills: 10 ranks
Current modifiers look like this: Balance +8, Climb +12, Hide +6*, Jump +20, Move Silently +8, Spot +5
Feats: 3
Environment: Warm plains (like a lion)?
Treasure: x
Type B looks like standard treasure.
Alignment: Always chaotic neutral?
Standard treasure and Always CN is fine by me.
Advancement: x
I currently don't have strong feelings about any particular advancement.
Why the progressive Dex effect? Isn't it their solidifying webs that gradually restrict their victim's mobility, while their venom just kills and liquefies?
You know, I was confused when I read the poison before and mixed it up with the web. Should we somehow revise the web (to make it progressively harder to escape) and poison back to Con damage only (adding liquification maybe)?
Cleon's skills and feats sound good to me.
Advance it like a lion: 8-13HD (Large)?
I'm not real fond of the "solidifying webs", as it will result in a clunky mechanic. I think the Con and Dex damage poison is a reasonable replacement. But I'll bow to the majority if that's what you all prefer.
The liquefication could be mimiced with the usual "can't be raised" mechanic, and is probably reasonable at its CR like the barghest.