Nickname Dilemma

I have 4 children; all of whom have been given long, somewhat complicated names. My first 3 were born with simplified, 3-letter nicknames. I was hoping to keep up the trend with child number 4, but for some reason it just hasn't happened. No one can seem to agree on one that fits.

I must have created an imaginary scenario in my head because I could have sworn that we had decided on Mal, before he was even born. Well, I'm the only one who remembers that agreement and therefore in the meantime we call him by his full name, Malachi.

I often shorten it-or elongate it-with silly little rhyming names. My favorite so far is Moe-Moe, or Moe for short. I'm also still keen on Mal. I don't want to confuse the poor boy, but we may just have to call him every random name we think up until one sticks; or maybe just keep it long?

What do you think? I know the ultimate decision is up to us, as the parents, but it's always fun to hear what others think.

I added a poll to the side bar--polls are great! Cast your vote, if you dare...

To add more info to your decision, my 3 oldest are named:

Thaddeus, or Tad
Athalia, or Ati
Elias, or Eli

and

Malachi, or...?

Thanks for your input!