Son left holding revolting pet snake ... it could get mum going up the wall! (10)
I believe the answer is:
stepladder
'snake it could get mum going up the wall' is the definition.
I can't tell whether this definition defines the answer.
'son left holding revolting pet' is the wordplay.
'son' becomes 's' (genealogical abbreviation for son).
'left' becomes 'ladder' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'holding' indicates putting letters inside.
'revolting' indicates an anagram.
's'+'ladder'='sladder'
'pet' anagrammed gives 'tep'.
'sladder' enclosing 'tep' is 'STEPLADDER'.
Can you help me to learn more?
(Other definitions for stepladder that I've seen before include "Short folding climbing frame" , "Decorator's platform" , "Help for climber" , "Portable climbing aid" , "Painter's mate" .)