Recently as a player my party fought against a creature that could paralyze you if you looked at it. Since my rogue has now seen it, would it be possible to replicate this using Minor Illusion by creating a image of the creature, and would it work the same way or be less effective? Could this also be used to replicate the attack the creature used that could kill if you failed the saving throw?
Illusions do not have a creature's features.
Illusions are not the creatures represented in them, so they do not have the features or attacks allotted to creatures of that form.
Minor Illusion is a cantrip.
Being able to replicate an area of effect Paralyze attack with a cantrip is well beyond the power intended by designers.
Minor Illusion doesn't create images of creatures.
Minor Illusion creates an image of either a sound or object. Creatures are neither.
This doesn't mean you can't use it as a bluff.
Minor Illusion does not require Verbal components. To opponents unfamiliar with the spell, you can say whatever you want, even the Verbal Components to a Summoning spell or simply say "Come forth, Medusa!" If your opponent believes you and understands what a Medusa is, it may still be tactically advantageous for them to avert their gaze from the direction of your "summon", granting effective invisibility to things in that direction. What appears before those that look would instead be something like a 5-ft statue or something otherwise appropriate of the spell.
Minor Illusion can't do this
There are two points where this fails:
Firstly, minor illusion can't create images of creatures. Its effect is
You create a sound or an image of an object within range that lasts for the duration.
and objects aren't creatures.
Secondly, (and this also applies to silent image which can create images of creatures) illusions of creatures aren't creatures. If the illusion were treated as a full creature the spell's description would say so.
Also note that this working would make the silent image spell way more powerful than it's normal 1st level (It would be a repeating, AoE hold monster (a 5th level spell)).