The neck needs to be approx between 10/12 fingers in length followed by two 5 finger bubbles for the front legs that are twisted around the bottom of the neck.

With luck and a fair wind, or something like that
Your finished giraffe will look similar to this;

TOP TIP
So that the giraffe's legs wont come undone when you twist the front legs pull the rest of the balloon in between them and with the back legs push the tail between the giraffe's legs so making two genuine lock twists. More details on the loop/lock twist can be found here;
http://www.balloonchat.co.uk/viewtopic.php?f=25&t=1091

Also, once you have a little more experience, add a mocha 160. Twist a 1.5cm bubble followed by two one cm bubbles and a matching 1.5 cm bubble lock them together by wrapping the nozzle round and pushing it through between the bubbles. Twist these bubbles around the ears of the giraffe and then start twisting a long string or 1cm round bubbles from the back of its head down its neck to the join where the neck meets the front legs. Make just enough bubbles to reach that joint and then wrap the 160 around the join. Squeeze the air out as you wrap the remainder around your fingers, snap or cut off the end and tie it securely. Cut off any excess.