There are many types of dwarf retics. The most common dwarf retic is the Jampea dwarf. Even so the largest one at the moment is some 15'+. Jampea retics are nice to look at and are VERY active. They're going to do what they want. There is no stopping a snake that size trying to do what it wants to do.

Here are two buddies of mine with the largest Jampea retic that I know of. The smaller one is about 6' and the other is about 6' 6".
YouTube - Big Jampea