Haha-Yes/commands/utility/avatar.js

const { Command } = require('discord-akairo');

class AvatarCommand extends Command {
    constructor() {
        super('avatar', {
            aliases: ['avatar', 'avy'],
            category: 'utility',
            args: [
                {
                    id: 'user',
                    type: 'user'
                }
            ],
            description: {
				content: 'Show avatar of the mentioned user or you',
				usage: '(optional) [@user]',
				examples: ['', '@user']
			}
        });
    }

    async exec(message, args) {
        if (!args.user) // While these kind of statments work you really should use {}
            return message.channel.send(`Your avatar:\n${message.author.displayAvatarURL}`);
        else
            return message.channel.send(`${args.user.username}'s avatar:\n${args.user.displayAvatarURL}`);
    }
}

module.exports = AvatarCommand;