To summarize the bdelloid rotifers, they have genes in their dna that have been incorporated from other kinds of organisms which have also given them functional/useful adaptations. I want to design a creature that has a similar ability but I don't know how well this ability might translate to larger organisms than these tiny freshwater invertebrates.
The end result would be a highly adaptive creature that averages at 100kg, smaller and larger specimens obviously being possible, that would be able to move into essentially any area of the world and skip all of the hard work of normal adaptation by consuming or using some other way to acquire the genetic material of other native organisms that have already spent millions of years adapting to the local environment. Whether the creatures would hoard genetic material until they reproduce or adapt on the fly through some sort of constant puberty or period of active metamorphosis I've not yet decided, but if any of those would make the ability easier/more plausible/feasible to have, one or the other whichever most applicable would be the assumed method of adaptation.
They'd no doubt steal from sapients at some point, so a variant of the species would arise that has the intelligence to fully make use of its species' abilities.
Can such a gene stealing ability work when scaled up for larger creatures or is it only really feasible when you're tiny?