Revelation 8:11
And the name of the star is called Wormwood: and the third part of the waters became wormwood; and many men died of the waters, because they were made bitter.
Cross-reference
Revelation 9:15 continues the trumpet judgments with a plague killing a third of mankind, expanding this earlier judgment's theme of destruction.
Revelation 16:4 turns waters to blood in a later plague, expanding the theme of water-based judgment from this trumpet.
Exodus 15:23 shows bitter waters at Marah that God sweetens, contrasting with this plague where bitter waters bring death without remedy.
Deuteronomy 29:18 warns against a root bearing poisonous/bitter fruit (wormwood) — the same imagery of bitterness from unfaithfulness as the star Wormwood brings.
In Ruth 1:20, Naomi renames herself Mara (bitter) due to God's affliction — mirroring the bitter waters of Wormwood as divine judgment.
Proverbs 5:4 describes the forbidden woman's end as bitter as wormwood — the same imagery of bitterness and destruction used for the star's effects here.
Jeremiah 9:15 has God giving wormwood and poisonous water as judgment — directly parallel to the bitter waters from the star Wormwood causing death.
Jeremiah 23:15 uses the same 'bitter water' imagery for divine judgment on false prophets, foreshadowing this end-times plague.
Lamentations 3:19 explicitly mentions 'wormwood' as a symbol of affliction, directly echoing this plague's name and bitter judgment.
Amos 5:7 uses 'wormwood' to condemn those who turn justice bitter, linking to this judgment where bitter waters bring death.