Slugs are already the recipients of bad press for ravaging crops and generally being a rather disgusting and slimy presence in dirt—and the general public attitude toward them isn’t about to get any better. The Telegraph reports that a large species resistant to common control methods has invaded the UK, mating with native slugs to create a massive threat to tomatoes and even small rodents.

The species under investigation is Arion vulgaris, an accurate label for the 6-inch gastropod that’s so brazen it feasts on dead mice, dog feces, and even other members of its species, which has earned it the name of “Spanish cannibal slug.” First spotted in 2010 in the UK and believed to have been brought over from salad leaves, the ambitious slug appears to have increased in number and is currently busy mating with native slugs.

Frank Schwichtenberg via Wikimedia Commons // CC BY 3.0

The result of that coupling might lead to even more terrifying behavior. According to University of Aberdeen’s Leslie Noble, the cannibal slug could see its gene begin to dominate the pool, leading to a hybrid super slug that can tolerate both hot and cold weather.

Arion vulgaris is already a handful. In addition to devouring crops, it’s known to laugh off attempts to poison it by way of slug pellets. It produces so much slime that predators like birds often wind up ignoring it.

Experts say that the slug’s continued mating habits and durability could wind up posing a significant threat to food supplies, although further research will be needed to assess the exact danger.

[h/t Telegraph]