Pooh states once "He always seems bigger because of his bounces", implying that the other animals think of Tigger as being larger than he truly is. That assessment fits well with Tigger's personality and his assessment of his own abilities, which he always overestimates. He is cheerful, outgoing, competitive in a friendly way, and completely confident in himself. Some of the things which he claims Tiggers can do include flying, jumping farther than a kangaroo, swimming, climbing trees. He never actually attempts any of the first three things in the course of the story, but he does try to climb a tree. He only succeeds half-way, being able to climb up but not to climb down again.
"Bouncy, Trouncy, Flouncy, Pouncy, Fun! Fun! Fun! Fun! FUN!" .... "The wonderful thing about tiggers is, I'm the only one!"
Need I say more?