To answer that question, we turn to fellow ESPN Insider Kevin Pelton, whose SCHOENE player projection system uses key player stats, as well as height and weight, to identify the most similar predecessors at the same age (ranked from zero to 100, with 100 being the most similar).
For Drummond, that's Dwight Howard. By a healthy margin.
Most similar to Drummond by SCHOENE similarity score
Dwight Howard 93.2
Andris Biedrins 91.4
Derrick Favors 91.3
Kevin Garnett 91.1
Josh Smith 90.6
Like Drummond, Howard came into the league at a similar age and height, but Howard received more minutes from the start, which is why their per-game stats don't match up well. Howard averaged 32.6 minutes per game in his debut season, far more than Drummond's 19.8 this season.
But on a per-36 minute level, we see Howard's averages of 13.2 points, 11.2 rebounds and 1.8 blocks with 9.1 shots per game are almost an exact replica of Drummond's season. Smart folks such as ESPN.com's Beckley Mason have made a comparison to Chandler, both in statistics and scoring style, but SCHOENE likes the Howard comp the best so far.