I am wondering if there is a certain card out there that will enable me to have more than 4 of one character card. Is there a land, enchantment, artifact ect. that will allow me to have more than four of the same type of one creature?

No. There are only specific creatures that allow you to play more than 4 of that creature. Relentless Rats and I can't remember the other one

But there are cards which give you tokens of creatures.
Is there a certain card you want to have more than 4 times in your deck?

Thank you for getting back to me. I do know of those two black cards that allow more than one. I just figured there was an old enchantment or artifact that would also do so. I was attempting to use a bunch of Ornithopter in a deck build.

Rite of Replication is also a possibility.
Progenitor Mimic
Supplant form
To name some others

Thank you for the suggestions. Not quite the angle I was going but this did open a new door for me.

There isn't a card that actually removes the only 4x restriction that I'm aware of (not even conspiracies). Sadly, outside of Relentless Rats and Shadowborn Apostle you will have to just look for functional reprints a la Llanowar Elves = Fyndhorn Elves = Elvish Mystic.

I was afraid of that. Ah it was a good thought at least. I am coming up with zero ideas as well. Aside from the two creatures mentioned.

I've always enjoyed Pack Rat. Not quite exempt from the 4-of restriction, but still manages to circumvent it in its own way.