Lizardfolk have a feature that gives them natural weapons in the form of their jaws. This bite deals 1d6+Str damage.
Hungry Jaws. In battle, you can throw yourself into a vicious feeding frenzy. As a bonus action, you can make a special attack with your bite. If the attack hits, it deals its normal damage, and you gain temporary hit points (minimum of 1) equal to your Constitution modifier, and you can't use this trait again until you finish a short or long rest. (VGM 113)
Assuming you transform into a beast shape with the ability to perform a bite, the Hungry Jaws trait should be available to you, as racial features transfer over when you transform if the new form is capable of them.
Given this circumstance, would you use the Lizardfolk's racial bite, or the bite attack belonging to the new form?