- Surprise!
- Why, thank you, Rabbit. Is it my birthday again so soon?

9 seconds sound clip from The New Adventures of Winnie the Pooh - The Masked Offender / Things That Go Piglet in the Night (S1E14).

You can hear this line at 00:15:14.786 in the Blu-ray version of the TV Series.

Quote context

[...]

- Hey, Eeyore, whatcha doin' out here actin' all scary like?

- Learnin' to swing. Don't get a chance during the day.

- Oh, the poor guy.

- Well, don't worry. I'll learn you to swing like a nightingale.

- I can hardly wait.

- Eh, what I want to know is how we're supposed to catch a ghost.

- Surprise!

- Why, thank you, Rabbit. Is it my birthday again so soon?

- No, no, no. We have to catch the ghost by surprise.

- I'll surprise him... with this.

- Hoo-hoo. I say, I do hate to bring this up, but before we confront the apparition, we do have to find him, don't we?

- That's right. Unless he finds us first.

- Since you're havin' trouble holding onto the swing, this glue will hold the swing onto you. Hoo-hoo-hoo-hoo-hoo!

[...]