In the process, however, Gustavo made many serious enemies.

It had also made him some very serious enemies.

If he lives, he is a more serious enemy even than we knew.

The most serious enemy of the mountain goat is snow, or more precisely avalanches.

Suffice it to say, they were serious enemies, too.

In his twentythree years of life, he had never made a serious enemy.

You're going to have one very serious enemy really soon, my lad, unless you help us out right now!

Papa made more serious enemies within the bureaucracy of the church.

Over his years of service, he had accumulated a great many friends and very few serious enemies.

Adult giant otters have no serious natural enemies, beyond humans.