He of the vast riches?
Only Bill Gates and Warren Buffett are higher than him on the list of wealthiest Americans, thanks to his estimated $36bn (£23bn) pile. It's 35 years since he founded Oracle, and it has moved well beyond database software, into hardware and IT services, where it butts heads with other tech giants.
Ah, butting heads, his favourite pastime
Fancy cars, big houses, tennis tournaments and sailing might rank above butting heads when it comes to his recreational activities, but at Oracle he is quite the aggressor.
What's he up to now?
Headed to court.
You're right. It has seemed like an endless round of legal tussles these last couple of years. Mr Ellison took the stand when Oracle took on German software rival SAP, claiming it stole customer data, and there's a retrial this summer. He also goaded Hewlett-Packard by hiring Mark Hurd after he was ousted as HP's chief executive.
The opponent this time?
Google. Oracle claims Google's Android smartphone operating system infringes patents and copyrights it owns on the Java programming language.
That sounds a big deal
Certainly Mr Ellison thinks so. Oracle is claiming $1bn in damages. Expect him in the witness box saying Java was the main reason he paid $7.4bn to buy Sun Microsystems in 2009.
Even if it loses, it reckons damages ought to be less than $100m. The trial could throw up some interesting financial secrets about Android, though, so watch this space.
Why can't everyone just get along?
That'll be the billions of dollars at stake in mobile computing, where every tech company has overlapping patents. A judge had ordered Mr Ellison to sit down with Larry Page of Google to try to reach a deal, but the talks lasted about five minutes. And that's not just because Mr Ellison loves butting heads.