Tentacles from Below (Passive)

As a reaction to either personally dealing or receiving damage, a sputtering of air bubbles emerge from the surrounding area, within thirty feet of you, at the start of your next turn.
(As a reminder, reactions can only been done once per combat round.) 

These tentacles are fifteen feet tall with a shimmering tone that matches the caster's skin color, with an occasional ethereal streak of electric blue or bright magenta.