Why pierce your ears? Why dye your hair? Why get tattoos? Why buy fashionable clothing? Makeup?
The OP may be able to give you a specific reason for why he chose to do it.
Body mods in general are for aesthetic and spiritual purposes and self expression.
Sorry, but this isn't a good comparision. People get ear piercings, makeup, clothes and hair dye to look better. These extreme modifications do not make people look better. You can say all you want that it's self expression, but what is it you are trying to express? That you can do weird things to your body? That you have dreams of being a lizard? That is is possible to cut a tongue or stick pieces of metal through yourself? Please, enlighten me. I knew it was possible to do these things without going out and doing them, and messing up my body for life. Only 3rd world countries do this for religious purposes. I have yet to see anyone say "Well, I don't want to split my tongue...but my religion says I have to, so I guess I will...". Trying to justify it religiously/spiritually is BS.
People do this to themselves because they want attention and haven't figured out how to get it by actually achieving something. That's why you mainly see teenagers/young adults doing it, because they want attention and this is a "rebellious" way to do it.
If your priority in life is trying to find ways to look freakish, that makes me not want to associate with you. It just looks like you don't think about the long term consequences of your actions. I think most employers would agree with that as well.
Sorry OP, what you did is definitely shocking, but it doesn't make me think of you in a positive way.
I hope any teenagers reading this realize that getting these things done will make people NOT take you seriously for the rest of your life. Get piercings if you want, you can at least pull those out when you grow up, but doing things like this will give you a lot of trouble when you want to be taken seriously in the world. You will be held back considerable.