You can buy the Wood Frog Box from him for less than one gold! Yet I've sold the same pet in the Auction House for 1000g at least 20 times now. If the Darkmoon Faire is located in the opposing faction's zone or Outland, this method works better since there is usually no one else selling the pet then. I'm a Horde player so if the Faire is next to Thunder Bluff, the AH has usually 1-3 of these pets for sale so I can't sell as fast then.
The item has about 10 min respawn time. While here, you should also check what Lhara has for sale. She too restocks fast and always has valuable herbs or motes for sale that give instant profit! For example, 2 Nightmare Vines cost less than one gold total, yet they sell for about 25g each in the AH atm!
And Heavy Knothide Leathers are worth almost 50g!
Camp Flik for a while. Buy loads of Wood Frogs and relist them in the AH 1 (one) at a time, so it looks more valuable! Put a price tag of 999g on it. It won't go instantly so patience is needed. I usually can sell one every 3 days, and when the Faire has left, I buyout the undercutters (If any) so I can dominate the Wood Frog sale.
You should also buy a couple of Tree Frog Boxes. They usually sell for about 30-50g, except if no one else is selling, you can add a zero to the price!
Tip: Not sure where the Darkmoon is Located? Open the ingame calendar and click on the event. It tells you the location!
★ Check the Elite Gold Making page for the best gold making tricks ★
★ Use the automated gold making addon and make 30,000 gold a day ★
★ Read the Most Secret Gold Making Tricks that even I cannot mention! ★
★ Level alts & professions. 1-90 in 2½ days is the record with this addon ★