Hissy

Fledgling: This creature transforms after the opponents turn

"Hissy is actually an alternative starter pokemon. If
you are too late for the traditional 3 starters, but
not qualified as a "sleepy boy" to get a Pikachu, you
may get a Hissy. Your local Pokemon Professor will
describe Hissy as "Not just one bird, but a whole
lots of birds"."