You and I organise sale of animal (6)
I believe the answer is:
weasel
'animal' is the definition.
(I've seen this before)
'you and i organise sale' is the wordplay.
'you and i' becomes 'we' (we means you and I).
'organise' indicates anagramming the letters.
'sale' with letters rearranged gives 'asel'.
'we'+'asel'='WEASEL'
'of' is the link.
(Other definitions for weasel that I've seen before include "Carnivorous mammal; treacherous person" , "Seal we turn into a long thin mammal" , "Double-dealer" , "Small fierce animal with slender body and reddish fur" , "Small fierce animal with slender body and reddish-brown fur" .)