Extra life loop:
Use Tinkerbell to fill up your power on level 1. Then, fly to the right and enter the cave filled with spikes. Carefully move through the cave until collecting a 3-Up. Intentionally die and repeat this process to accumulate 99 lives,

Fall into the first chasm on the right at the beginning of level five (the caves). Walk or fly to Tinkerbell on the bottom of this area. A leaf will appear with a 3-Up. Lose your current life and repeat the process to accumulate 99 lives.