Mega neon giraffe? That’s extremely rare, since the safari egg isn’t available anymore, so you can’t get a giraffe from eggs, let alone 16 of them.
The only way you can get a giraffe is by trading, and not a lot of people have giraffes, so you’re gonna have to do a LOT of trading.
Also, considering that you only have a dog, try to acquire some more valuable pets (if you have robux, buy some robux-only pets), perhaps rare, ultra-rare, or legendary (events are a great way to get legendary pets). Then, work your way up by trading (ex. trading a narwhal for a starfish, then trading that starfish for a unicorn) until you get a legendary pet that isn’t available anymore. Then, trade it for a giraffe. You’re gonna have to do it 16 times, so find some time (a few hours) to play Adopt Me and get the 16 required giraffes.