I can't seem to find any monster battler games for PC (not counting Pokemon hacks and such, of course). I can't even find any indie games that are what I'm looking for. The closest I've found is the pet battle system for World of Warcraft but I'm not paying $15 a month for that. On home consoles and handhelds (admittedly almost all for Nintendo systems) there is Pokemon, Robopon, Dragon Quest Monsters, Yo-kai Watch, Monster Rancher (I think), etc.

Do developers not think this little genre appeals to PC users? Surely I'm not the only guy out there that wants to raise a dragon to its peak and then pit it against a T-rex in pitched combat. They don't have to be aimed at a younger market either. Developers could make it more mature if they wanted to. We got a Mario Kart clone in the form of Wacky Wheels. Just seems odd there isn't a notable Pokemon clone.

Mature or not I wish there was more monster battler type games on PC. All I want to do is collect and battle with weird monsters. Anyone know of any that I just missed (again not counting Pokemon hacks)? Anyone else actually interested in these types of games being made for PC?

There is Zanzarah: The Hidden Portal (2002) on PC. Be aware that many users complain that it doesn't run well on modern rigs. I didn't notice any major issues on my Win 8.1 setup, but that's no guarantee it would run on yours, and I've only played a few hours. Still, at the current sale price it might be worth a try, if you're fine with using Steam.

I also found some indie and browser/online games that might fit the description, but I'm not familiar with them myself:
- Deity Quest
- Siralim
- Siralim 2
- Digimon Masters Online
- Monster MMORPG
- Pokemon Zeta/Omicron (beta)

The Geneforge Saga allows you to create your own creatures to fight for you, but it's probably not quite the Monster Battler game you're looking for, more a traditional RPG. You could check it out anyway.

Not counting hacks and emulators, hmm. I guess this is all I can find:

Siralim: Not familiar with this one, but apparently it's a monster summoning roguelike that's well reviewed.

Minimon: This one seems heavily inspired by Pokémon, but it's still in early access.

Digimon Masters Online: It's a free-to-play MMO, don't know how close it is to the other Digimon games.

Ni no Kuni II: This one comes out in a month, but if it's anything like the first one, it's about recruiting monsters to fight alongside you and level them up.

World of Final Fantasy: It's about collecting chibi versions of classic Final Fantasy monsters. The human characters also fight alongside the monsters.

Final Fantasy X/X-2 HD Remaster: I remember them having an entirely optional, yet very robust, monster capture/battling minigame/side-quest. I think it's necessary to fight the strongest bosses and unlock some of the most powerful abilities.

That was all I could come up with, but keep in mind that when it comes to Pokémon clones, and that includes the non-PC ones you listed, they're just not very good. The Pokémon games, and perhaps the SMT games if you want to count them in, appear to be the only ones that are regarded as great among the genre.

EDIT: Got ninja'd by an edit on a couple of these.

That's what I kept coming across in my search. I guess it isn't entirely a lack of monster battlers but a lack of quality ones especially.

Thanks for the suggestions. I'm guessing there are none on GOG since both of you link to Steam mostly. I know Geneforge is here though.

Get World of Warcraft, start Pet battles