The name "tsutakaaku" has not been assigned to any pokemon as of now. However it could be the evolved form of Tsutaja, the grass type, since it hasn't been assigned a name yet, and pokemon evolution chains tend to have the same prefixes and suffixes, (POLIwag, POLIwhirl, POLIwrath, POLItoed) but that's just a guess. It hasn't been confirmed yet, so only time will tell.