Play NYT Connections Puzzle #603 Wed, Jan 1

Find groups of four related words Need hints?

Solve NYT Connections puzzle #603 - Group 16 words into 4 categories: EARTHWORM, EEL, SALAMANDER, SLUG, AURORA, FIREFLY, GLOWSTICK, RADIUM, CANAL, CLOG, TULIP, WINDMILL, GATECRASH, RAINDROP, SKYDIVE, WATERFALL.