Creator of placard nibbled by ruminants (8)
I believe the answer is:
designer
'creator' is the definition.
(I know that designer subproperty of creator)
'placard nibbled by ruminants' is the wordplay.
'placard' becomes 'sign' (I've seen this in another clue).
'nibbled by' is an insertion indicator.
'ruminants' becomes 'deer' (deer are a type of ruminant).
'sign' inserted within 'deer' is 'DESIGNER'.
'of' acts as a link.
(Other definitions for designer that I've seen before include "Custom-made" , "Who draws" , "Fashionable" , "One who determines the look of something" , "Theatre set creator" .)