I have just started using the Desmodus elixir for imprinting babies and it does not work on water creatures, such as tusoteuthis. Can you somehow remedy this? It seems that since you cannot 'consume' items under water, the elixir just stays right there on the hotbar unconsumed, therefore the baby it is intended for does not get the additional imprint. I have not tried it while sitting on a shadowmane, though I intend to experiment with that to see if it works that way. My guess is that since the shadowmane is already grown, the elixir may either still not be consumed, or may have no effect on anything. We shall see. ... off to experimenting.
Update: sitting on shadowmane does not work, nor does sitting on a chair. Although one can consume food items in both those situations, one is unable to consume the elixir.