He is that big, at 6'8" and at 19 and a half stones, and that hard, he rendered Bismarck du Plessis unconscious this season, as well as getting carried away in an attempt to head-butt Australia's Nathan Sharpe.
"Yeah, he is very, very big. He's very aggressive, very powerful with ball in hand and very explosive at the line-out, where he is also very clever. He is certainly one to be looking out for," noted Ireland lock Ryan.
Etzebeth has earned a reputation for a quick temper in a short space of time. There is something of an incendiary device about him. Will that be a factor?
"I don't know. You always walk a tightrope with that, having a short fuse.
"It really adds if you have that eagerness and others can roll in behind you. It can be a good thing and a bad thing".
In a land of giants, a teenager has to possess super-human powers to be dropped straight into the Springboks engine room.
Just before South Africa boarded their flight for the northern hemisphere, Etzebeth attended the prestigious South African Rugby Union (SARU) Rugby Player of the Year Awards as a three-category nominee.
He was short-listed for the Rugby Player of the Year, Young Player of the Year and Vodacom Super Rugby Player of the Year for performances for the Springboks, DHL Stormers in the Super-15 and DHL Western Province in The Currie Cup.
In the end, he had to settle for the Young Player of the Year.
In contrast, Ryan, then 17, thought he made it big as a Munster Youth and Ireland Youth international until he arrived at St Munchin's College to find out he wasn't quite 'The Man'.
The Neneagh forward had to wait until 2008 to make his Ireland debut as a replacement against Argentina. He had to bide his time for his first start. It came against Scotland in a World Cup warm-up in August 2011. He was 27.
He is finally beginning to look and play the part of a fully-fledged international second row.