He was one of about 16 a year that are spotted on the Otago coast after a more than 2500km swim from the Antarctic.
The impressively toothed creature - they dine on penguins - was more than 2m long, and kept a close eye on photographers.
Department of Conservation biodiversity ranger Jim Fyfe said leopard seals bred around the Antarctic ice shelf, but each winter they left the cold of the Antarctic waters. Some came as far north as New Zealand.
Each year a small number arrived on the Otago coast, and were usually seen here between June and late November.
Mr Fyfe said numbers had increased recently. Records of sightings had been kept since 1999, and showed from an average of four a year they jumped in 2009 to 26, and after that averaged more than 16.
This year the first was seen at Waikouaiti Beach in late July, with six more seen since then.
Leopard seals were distinctive, with a prominent head often described as ''reptilian or prehistoric''. Mr Fyfe said it was usually younger, smaller leopard seals that arrived in Otago.
Leopard seal numbers were thought to total more than 100,000.
They were a ''top predator'' that fed on penguins in the Antarctic, and had been seen feeding on shags in Otago Harbour and muttonbirds off the coast.
They also ate fish, including elephant fish.
Mr Fyfe said the animals came ashore to rest.
They were not particularly mobile; their short fore-flippers meant they moved ''a bit like a caterpillar'' on the beach.
But he warned people to keep their distance from the creatures.
''They can swivel around really quickly and they have very impressive teeth.
''You wouldn't want to mess with those.
''Give them lots of space, respect them as a wild animal, keep your dog away.''
Doc was keen to hear of sightings so it could understand leopard seals' habitat use and manage threats they faced while visiting the region.
