Muirm and Methatraus

Muirm: They dig a network of tunnels into ice caps, feeding on algae. The spikes around their necks are their only weapon.

Methatraus: The crystal stumps on their bodies have a small hole in them. They can project liquid nitrogen through them as defense.

The two can only live in cold places. So Methatraus will also spew methane gas to slightly heat up the glacier it lives on. This creates avalanches that can burrow a nearby area (like a village) and thus expand their territory for a short period of time. This comes in handy when they are looking for food.