Doctor, I will follow the guy with the West African monkey (8)
I believe the answer is:
mandrill
'west african monkey' is the definition.
'mandrill' can be an answer for 'monkey' (mandrill is a kind of monkey). I'm not certain of the 'west african' bit.
'doctor i will follow the guy' is the wordplay.
'doctor' becomes 'dr' (abbreviation).
'i will' becomes 'I'll' (abbreviation).
'follow' means one lot of letters go next to another.
'the guy' becomes 'man' (guy can informally mean a man).
'dr'+'ill'='drill'
'drill' put after 'man' is 'MANDRILL'.
'with the' is the link.
Can you help me to learn more?
(Other definitions for mandrill that I've seen before include "West African baboon" , "West African baboon-like primate" , "Monkey with red and blue hindquarters" , "Baboon with colourful face" , "Colourful baboon in the damn rill" .)