Not sure how the magical effects of the monsters mentioned would translate over to a sci-fi/space opera setting.
Given the Zhodani presence there could be psionic creature that get called monsters.
Here are some thoughts. Updates to Psion abnilities will change these options of course.
No recent psionic publication, so going back to first edition psion book you get Advanced Psionic Talents. These could make nasty "monsters".
Luminokinesis could have beasts that make things darker, allowing their attacks to come in darkness.
Energy draining beasties could drain power armour. Put them in packs and the player's power armour becomes a tomb.
The Chilling Dread is a monster that sustains itself by puling heat from its prey with Thermokinesis.
The Witch could use Glamour to be invisible before its attacks, or buff itself with physical enhancements to be a tough opponent with personal enhancement or the Awareness skills in the Core book.
The basilisk could have the Pain advanced talent and blast victims into helpless fetal positioned targets with its mental attack.
The Medusa paralyzes victims with the Paralysis Talent, while the Gorgon's ability to Mind Blast an area and cause stupendous damage is devastating to targets.
Then there are the Vampires, those degenerate Zhodani who took the Tapping ability too close to heart and create huge reserves of Psi Points by draining their thralls and storing the points. This grants them the high level DM's on pg 3 of the Traveller Companion.
Dementors or psychic vampires use Tap Emotions to drain all the fun and emotion from their victims, leaving a shell behind.
A Mind Switch creature that swaps out their mind using the Mind Switch Talent makes the swapped player the prey from their own party, all for the sick delight of the creature who made the switch.
That is about as magical as I can think of off the top of my head. You will have to make their Skill Levels pretty high, and address any high tech anti Psi gear owned by the group.
