His rebounding numbers are monstrous.
Peak Rodman level.
His 18.36% offensive rebounding percentage is the highest since 97 Rodman who played 3 less minutes and was in much more of a specialist/roleplayer role.
Before that there is really no other guy who can compare except for Moses Malone the GOAT offensive rebounder.
Oh and Jayson Williams arguably has the best Peak year for ORebounding with an absurd 20.5% ORB rate back in 1998.
He also shot .666 from the FT line that year.
Drummond's 27.9 TRB% percentage is the highest ever
or since 71 when the stat started getting tracked for those who qualified according to BBREF.
Rodman bettered him (once) in 1995 with a 29.7% mark.
So he has the second highest mark ever though 95 Rodman played 6-mpg less and in a smaller role.
Outside of Rodman no one really approaches him.
Ben Wallace hit 23% once.
DeAndre hit 24.5% last year in 34-mpg.
Boerwinkle hit 22% in 71 (for Wilt fans)
But yeah from a statistical standpoint his current rebounding numbers are way off even the GOAT scale.
Obviously he is not going to maintain those numbers but still it is impressive.