You might disagree with the definition of P2W, and that’s alright, but you have to acknowledge that the content of the Giant Snake pet is not available for free; it is an additional option that comes into the vast topic of balance because it is indeed a functionality and not something purely cosmetic.
“Pay to Win” is the general label given to those additional functionalities, because you cannot have something that is P2W without it bringing something to the table.
You can argue about the reciprocity, say that the Giant Snake brings something to the table, but that it isn’t advantageous; or you can acknowledge that the P2W label is being used in a broader sense.
Also, I’m not sure we have enough retrospective about the Giant Snake just yet, so we cannot say whether it is useless or not, whether it affects balance or not. It might be useful enough to truly be P2W in the strict sense, you might be able to use it in a clever way for base defense in PvP, combined with other things, who knows with the amount of combinations and possibilities in Conan 
Now yes that is a good point 
Which is basically what the majority of people have been saying 