Looking for 2 FF1: DOS monsters

I'm looking for 2 monsters to complete my bestiary. They are Flood Gigas and Undergrounder. I know they are found in Whisperwind but what floor types can I find them on, and do I have to be above level 30 to find them like some of the others?

Thanks.

Flood gigas are in the higher "marsh cave" levels of whisperwind cove. Undergrounders show up in the higher ice levels. They're both kinda rare, though. And I'm pretty sure it's over 30.