I am trying to make a lion head and I used a RTK recipe: 4 cups rice krispies , 5 cups marshmallows but without the butter but it is just not sticking together and just falling apart. I did crush some of the rice krispies. What's making it so soft and not holding its shape? I need help with this RKT ....

I find RKT really temperamental- sometimes if the marshmallows don't get hot enough they stay soft, you need to get them hot to change the structure of the sugars so that they then set hard. you could try microwaving on high taking care not to burn the krispies, if that doesn't work make a rough shape, wrap it tightly in cling wrap like a xmas cracker and keep twisting the ends to really squeeze it all together, even bash it with a rolling pin if you like. Put it in the freezer and it will go rock hard in about 10 mins (ooh if you're using a dowel or something to hold it on the cake poke this in before you freeze or you'll never get it in). When solid cover in melted white choc (messy) cling wrap and freeze again. It should hold up ok to decorate then, I made a tall tower 100percent RKT like this and had no probs in the end
HTH