Definition of "lizzard"

It is not denied there have been bicipitous Serpents with the head at each extream, for an example hereof we finde in Aristotle, and of the like form in Aldrovandus we meet with the Icon of a Lizzard; which double formations do often happen unto multiparous generations, more especially that of Serpents […]

1650, Thomas Browne, Pseudodoxia Epidemica: […], 2nd edition, London: […] A[braham] Miller, for Edw[ard] Dod and Nath[aniel] Ekins, […]