I was in a charity shop a while back when I came across two jellyfish ornaments, which I assume were from some aquarium gift shop. I decided they'd be good D&D or Rogue Trader monsters, then chucked them in a drawer and forgot about them. A while ago I pulled them out, only to learn that they're really too big and unstable for traditional GW-style flying bases.
If the model is big but not heavy, a great substitute for this kind of base is a plastic wine glass. You can get a pack of six of them for £1, and they allow flying models to occupy the same space as a model on the ground, since the mouth of the glass is open. I carefully trimmed down the stem with a pair of clippers, and hey presto. The photo doesn't capture the shimmery, slightly translucent effect of the plastic very well, so you'll just have to take my word that they are very nice jellyfish toys.
The alien being hovers over Inquisitor Stompheader. But what does it want?!