One of the racial features of lizardfolk is the Cunning Artisan trait (Volo's Guide to Monsters, p. 113), which states:
As part of a short rest, you can harvest bone and hide from a slain beast, construct, dragon, monstrosity, or plant creature of size Small or larger to create one of the following items: a shield, a club, a javelin, or 1d4 darts or blowgun needles.
Druids can learn the shillelagh cantrip:
The wood of a club or quarterstaff you are holding is imbued with nature's power.
The lizardfolk skill specifically calls out bone and hide, and the spell specifically calls out wood. But both are labeled as "a club".
Could the hand crafted club from a lizardfolk work as the club for shillelagh? What if they included a couple twigs and branches from a nearby tree?