Size Growth (object) – The ability to make an object and/or another person grow larger.
Henry Pym used this power when he was a member of the West Coast Avengers because his body could no longer take the strain of growing and shrinking (West Coast Avengers V1 #21).
There is a very good reason Henry Pym has never tried to take over the world with an army of giant ants (West Coast Avengers V2 #19).
If Henry Pym does get past the above glitch above then an army of giant ants then he might team up with the following species of intelligent ants that appeared in Uncanny Tales #38.
I did run into an interesting tale of a man who wants to create giant arthropods the old fashioned way (Uncanny Tales #38). Spiders are of course not insects but spiders and insects are both arthropods.
The Silver Age was filled with people getting turned into giants against their will (Action Comics V1 #325, Adventure Comics V1 #308, Adventure Comics V1 #315, Challengers of the Unknown V1 #36, House of Mystery V1 #143, Strange Adventures V1 #28, Strange Adventures V1 #112, Superboy V1 #50, Superman V1 #226, Wonder Woman V1 #136, Superboy V1 #50, Action Comics V1 #325 and Adventure Comics V1 #315, Aquaman V1 #2, Challengers of the Unknown V1 #20 and Challengers of the Unknown V1 #36, Adventure Comics V1 #308, Detective Comics V1 #243, House of Mystery V1 #143, House of Secrets V1 #11, Jimmy Olsen V1 #77, Strange Adventures V1 #112 , Strange Adventures V1 #28, Superman V1 #226, Wonder Woman V1 #136).
Size Lad (DC) can make objects shrink and grow in Adventure Comics V1 #337 (DC).
Muto (DC) uses an expander ray in Action Comics V1 #339.
Zunial (DC) uses a gigantizing ray in Superman V1 #188.
In The Food of the Gods and How It Came to Earth by H.G. Wells, a special food can make animals and humans larger (Classics Illustrated #160).
Tommy Tomorrow (DC) faces a sci-fi version of The Food of the Gods in Action Comics V1 #135.
Next Size Growth (self)