This is quite likely t' only Ember CLI addon that can work even if ye don't add it t' yer dependencies.

Ember Pirate provides an arr helper that accepts as many positional parameters as ye want and returns a collection with them all.

Ember Pirate can work even if ye do not declare it as a dependency.

ember install ember-pirate

ember generate helper arr

Do ye want to use Ember Pirate in yer twiddles but support for addons is not available? Good news! Ember Pirate can be used easily thar too.

Go t' Ember Twiddle, click File > Add... > Helper and change the path t' helpers/arr.js when prompted.

{{#with (arr "Me" "Second" "grog") as |collection|}}
  {{collection.firstObject}} love {{collection.lastObject}}
{{/with}}

Produces:

Me love grog