Best approach to rigging an alligator I've a nice mesh but would like the flexibility of rigging (joke intended).
Should I start with Rigify or create the bones myself? I'm familiar with bones and the skin modifier from 3dsmax but have little experience with blender. I'm using version 2.9
Rigify is able to do the job. Rigify is a modular rig system to create bones and controls with automatic or manual FK/IK. Keep in mind the settings for Rigify differ weather you're on edit mode (for the Armature), the pose mode (for bone constraints) and animation (drivers). There is a complete guide showing you step by step how to learn Rigify. The only guide I seriously recommend: https://gumroad.com/a/189101171
On Lesson 17 there is a full rig exercise with a dragon head, that way you can also learn how to rig blinking eyes for reptiles.
If you need further -specific setup answers- please post them here.