Currently, my student visa is still pending for NZ. However, I have already bought my ticket and I'll be flying out in a week. I have a Malaysian passport and I am from a waiver free country and can visit NZ visa free. Would I be able to enter NZ with a visitor visa and, once my student visa has been approved, transfer the visa onto my passport?
New Zealand allows you to change your visa while in the country. From Can I apply for any other visa while on a visitor visa in New Zealand?:
Apply to stay longer
If you're already in New Zealand and have a visa you can reapply for the same visa or apply for a different one.
The above includes applications which are in process when you enter the country. Note that you may not get an actual visa sticker when you do get approved - they may simply send you an email confirming your change of status that is recorded in their system. If you need proof of your student visa status (for enrolling or whatever), print this out.