How to represent Emblems

[Octopusman]

I looked around a bit:
From the Comprehensive Rules (Battle for Zendikar (September 26, 2015))
113. Emblems

113.1. Some effects put emblems into the command zone. An emblem is a marker used to represent an object that has one or more abilities, but no other characteristics.
113.2. An effect that creates an emblem is written “[Player] gets an emblem with [ability].” This means that [player] puts an emblem with [ability] into the command zone. The emblem is both owned and controlled by that player.
113.3. An emblem has no characteristics other than the abilities defined by the effect that created it. In particular, an emblem has no name, no types, no mana cost, and no color.
113.4. Abilities of emblems function in the command zone.
113.5. An emblem is neither a card nor a permanent. Emblem isn’t a card type.

An emblem is different from a card or a token.

All I can see is that it is a "marker". Are they like tokens or counters in that I can use anything to represent them? i.e. I can I use a penny, a sharpie, or a can of soda to represent them? Just making sure.

Kind regards,

[Anen]

You can use the official emblems you can find in boosters. Or anything you have under the hand, ala token, as long as it is clear what it is for both your opponent and you.

[Dice_Box]

You can write it on a scrap of paper, it doesn't matter how you choose to represent the Emblem, just as long as it's clear it's active.

[cdr]

Anything clear to both players is fine. At Competitive REL, it should also be reasonably clear to passing judges. I don't recommend using actual Magic cards.

[Octopusman]

At competitive REL do you think I could get away with using my Mario Amiibo as an emblem?

[Koby]

At competitive REL do you think I could get away with using my Mario Amiibo as an emblem?

This leaves a lot to be interpreted, but as long as both players are clear that it is acting for that purpose this would be sufficient.

Remember that communication should be clear and concise with your opponent.

[cdr]

At competitive REL do you think I could get away with using my Mario Amiibo as an emblem?

Sure, why not.