This mechanic in itself isn't particularly "lifey", IMO. We the adequately chosen name it could fit almost everywhere (
Burst,
Flash,
Eruption or what ever). In waves (specially those artificially started), the receding is beyond/under the original level (if you consider it to be the see/lake level). It is only after a while that the water stabilises itself and that it reaches its original flattened level. A "wave of power" or a "rising wave" (as OldTrees mentioned) would in this regard fit, IMO.
On an other hand, the animal rise above their expectations in the presence of stress that you describe correspond in my opinion to an adrenaline rush. This (as you know) has already been made into a card. This (as every drug) suffers a withdrawal (as you described) but will finally stabilise after a while (as the wave above).
I don't have a specific problem with this card being a life card. If you want to go on with it this way I won't argue against it. However, I consider that for a greater the game balance it is important to take into account not only the card itself but also its environment. As I said above, life has 2 buff cards and water none. Plus, this card being a water card would slightly strengthen the
/
(think of warden) and
/
(think of deathstalker) combos in a soft/subtle manner (which I like).