Most likely a surprise birthday present hidden up that tree.
5 seconds sound clip from The New Adventures of Winnie the Pooh - How Much is That Rabbit in the Window? (S1E10).
You can hear this line at 00:08:14.280 in the Blu-ray version of the TV Series.
Quote context
[...]
- Well, now, that should do it.
- Ha ha. Nothing like boiling your clothes to get them really clean.
- Oh, hello, there, Tigger, my good... no, no, no... my very best friend.
- Shh. Shh. I got a whatsamajigger cornered up this here tree.
- Oh. But I thought you borrowed one from my house.
- No, that's a whoosits. You use those to catch a whatchamadingle.
- Most likely a surprise birthday present hidden up that tree.
- Ohh hoo hoo! Ho ho! I'm so happy! Ha ha ha!
- Excuse me, sir, but you are a monster, aren't you?
[...]