The puppy followed at its owner's heels, matching every step.
Tips
history
From 《庄子·田子方》: a disciple complains 夫子步亦步,夫子趋亦趋 — when you walk I walk, when you trot I trot — but I can never catch up. Originally about admiration, now usually critical.
memory
亦 = also; 步 = walk; 趋 = run. 'Also walk, also run' — copying every move.