Mario lands with an 'oooff' as Pikachu falls upon his chest, then, as he sees the white rabbit escape them again, he says to the yellow rat: "Pika-pikaaa, pika chuu-chu!", meaning 'the next time we see that rabbit, please zap him before he can escape again.'
Then, looking around and noticing the little key and the curtains, he feels the first symptoms of a major headache.
"Please, look behind the curtains and tell me there is no very small door, and that the key doesn't open that lock."