JavaScript code:

function ele (name, attrs, ...children) {
    const element = document.createElement(name);
    for (const [key, value] of Object.entries(attributes)) {
        element.setAttribute(key, value);
    }
    for (const child of children) {
        if (typeof child === 'string') {
            element.appendChild(document.createTextNode(child));
        } else {
            element.appendChild(child);
        }
    }
    return element;
}

ele('div', { class: 'cat' },
    ele('div', { class: 'name' }, 'I\'m a cat'),
    ele('div', { class: 'avatar' },
        ele('img', { src: 'https://blahblah' })
    )
);