There are some VST instruments (plugins) that can morph their own sounds, so I suppose if you were able to load up two WAV files of your samples you morph between them.
Two VST plugins that I know that offer sound morphing or mutating between two or more audio sources are
Alchemy (Camel Audio). According to its manual “You can morph or crossfade between sources. You can import your own samples from SFZ, WAV or AIFF files.”
MorphoX (LinPlug). According to its Web site, “the sound can be continuously morphed between two individual sounds including effects using the modulation wheel.”
Absynth (Native Instruments) also has a waveform morphing function, so if you created two different sounds from within Absynth using its waveforms or custom Absynth waveforms you’ve created, you can morph them into a new waveform that Absynth calls a Morph Wave.
You can probably find other examples by searching the plugin database at KVR Audio (http://www.kvraudio.com/get.php).