Unfortunately, the PCs had levelled up a bit past a pack of six dire wolves. I couldn't think of how to escalate the encounter, to make it more interesting. I thought, "Oh, duh. Terrain!"
Looking through the stats of a dire wolf I discovered their Large size and high Strength meant they had a good standing high-jump. Since the wolves normally stay in their cave, I made these rock formations ... conveniently high enough for a dire wolf to jump up on. The PCs wouldn't be able to reach them, but the wolves would be able to jump down on undefended characters like the wizard!
These are made of foam insulation, painted with patching compound, acrylic latex paint and coated with matte varnish.