Yellow Planet

Narwhals and beluga whales do mate in the wild. The first "narluga" was captured in the 1980s and identified (by DNA testing its skull) in the 90s as being the first generation hybrid of a female narwhal and a male beluga whale. It even had lots of spiral horns like Maggie did, but it was a male, and since the narwhal horn is a tooth, he grew his inside his mouth, where teeth are usually found.

Orcas do eat beluga whales. And have eaten the majority of a pod in one sitting. Whales are a large enough part of Orcas diet that it's their name; Orca means "whale killer" not "killer whale", because they aren't whales but do eat them.