What could the etymology of Phallodriline be?
-o- linking vowel indicates Greek. -i- is Latin, unless the second word starts with a vowel (many -ectomy words for example). This is irrespective of declension or gender. Weird I know.

In fact, Latin phallus is from φαλλός.

The second part is worm δρῖλος (drilos). Actually it can also mean penis, but let's gloss over that...