I'm a rather unique example of a F2P, as I have a large amount of knowledge of the TF2 world, just that I'm not fully able to put this knowledge to use, also I belong to the shpee species.

A very new and EXTREMELY rare addition to the TF2 species archive.

Name: the Solly Dwarf
Scientific Name: Solidifcus Mineralus
Habitat: Anywhere where there are rocks to mine.
Rarity: Nearly non-exsistant, unless there is a large opulation of 'em living deep underground.
Behaviour: Passive/Agressive

As said in the rarity section, these creatures are supposedly very rare but people speculate that there are giant advanced underground colonies waiting to be discovered, the Solly Dwarves are hard workers mining for minerals, ores, bascially anything you can mine out of a rock that can be sold for some good dosh, the Solly Dawrfs main pecularity is that it's able to mine precious ores (e.g. Australium) out of seemingly normal rocks and are speculated to have invented the base to the TF2 currency (scrap, ref, rec) to make trading easier, showing how advenced the undisovered Solly Dwarf colonies could be.
The first public sighting of the Solly dwarf was a mistreated working colony found on pl_upward_abandoned, owned by a recently colsed mining company, these creatures show large amounts devotion to the only thing they know to do WELL, mine, if you ecounter a Solly Dwarf the right course of action is to leave it alone as Solly Dwarves are COMPLETELY oblivious to their enviroment when mining, but attacking a Solly Dwarf can cause it to become agressive, while killing it can temporarly activate it's ancient honour warrior instincts (fun fact: Solly Dwarces evolved from honour fighters) also known as the infamous "TRYHARD MODE" which causes it to become either a pissed off halerious faliure, or one of your worst nightmares (depends on the soldiers skill).
This here is at the moment the most info about the Solly Darf that I was able to gatherat the moment, but I guarantee you that I WILL attempt to discover more about this unique creature, I myself are a crappy Battlegenier/ young revolver Shpee, but I'm disgusing as a Solly Dwarf to attempt to discover more about 'em, hope to see ye soon chums (picked the phrase "chums" from a book), and I hope this will be added.