Patrick and Henry consumed by the Little Piggies heard going along the canals (8)
I believe the answer is:
towpaths
'going along the canals' is the definition.
'patrick and henry consumed by the little piggies' is the wordplay.
'patrick' becomes 'pat' (I've seen this in other clues).
'and' is a charade indicator (letters next to each other).
'henry' becomes 'h' ('H' can be a synonym of 'henry').
'consumed by' indicates putting letters inside.
'the little piggies' becomes 'tows' (I can't justify this - if you can you should give a lot more credence to this answer).
'pat'+'h'='path'
'path' placed within 'tows' is 'TOWPATHS'.
'heard' is the link.
I am not very happy about this link. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for towpaths that I've seen before include "Tracks along canals for animals pulling boats" , "What spot for the canal walkways" .)