When travelling, spot erratic old creature (11)

I believe the answer is:

triceratops

'old creature' is the definition.
(I've seen this before)

'when travelling spot erratic' is the wordplay.
'when travelling' indicates an anagram.
'spot'+'erratic'='spoterratic'
'spoterratic' anagrammed gives 'TRICERATOPS'.

(Other definitions for triceratops that I've seen before include "Old creature" , "Cretaceous herbivore" , "Three-horned dinosaur" , "Horned dinosaur" , "Extinct reptile" .)

I've seen this clue in The Guardian.

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