Goblin Cruciverbalist

Haste
When this creature enters, create a colorless artifact token named your choice of A, E, I, O, or U.
Whenever this creature attacks, using the first letters of the names of permanents you control, spell a word you haven't spelled this game. It gets +1/+0 until end of turn for each letter in that word.

Unfinity

You may consult a dictionary if not all players agree that you have chosen a cromulent word.

The token will have one of five names: A, E, I, O, or U. It won’t be named “your choice of A, E, I, O, or U.”

When determining the first letter of a name, ignore all spaces and punctuation, including blank lines.

Each time you spell a word, you can use the first letter of each permanent you control only once in that word. For example, if you control three permanents starting with A, B, and N, you can spell out the words “Ban” or “Nab,” but you can’t spell out “Banana” unless you gain control of two more A’s and another N.

The token doesn’t have any abilities and doesn’t usually do much except give you a vowel to work with when spelling words.

“Haven’t spelled this game” means for any game reason, including previous Goblin Cruciverbalists you controlled but not including words you just spelled for fun, like . . . um, people do. Keep track of the words you spell if you expect remembering them to be challenging.