Fungal growth in amphibians, likewise lizards originally (9)
I believe the answer is:
toadstool
'fungal growth' is the definition.
(I've seen this before)
'amphibians likewise lizards originally' is the wordplay.
'amphibians' becomes 'toads' (toad is a kind of amphibian).
'likewise' becomes 'too' (too can mean likewise or as well).
'originally' suggests taking the first letters.
The first letter of 'lizards' is 'l'.
'toads'+'too'+'l'='TOADSTOOL'
'in' is the link.
(Other definitions for toadstool that I've seen before include "Inedible fungus" , "Umbrella-shaped cap on a stalk" , "that could be poisonous" , "Plant akin to mushroom" , "Poisonous fungus" .)