From WikiGTA - The Complete Grand Theft Auto Walkthrough
Ivan the Terrible
Ivan Bytchkov is a Russian burglar who lives in Hove Beach, Broker. In the mission Ivan the Not So Terrible, Vladimir Glebov wants you to kill him. But you can choose to kill him or let him live. If you let him live, Ivan will come back later as a Random Character. Then he has changed his live in a money lender and Niko will help him by letting some people pay Ivan.