placeowl.com is an owl themed image placeholder service. Images are ubiquitous on the web. Web engineers often need stand-in images when developing web sites if designs are not complete or live content is unavailable.
That is where a placeholder image service is valuable. This site provides dynamically sized images as needed.
<img src="https://placeowl.com/300" />
This will insert an square, owl themed placeholder image sized 300 pixels wide and 300 pixels high. There’s more explanation and options listed at placeowl.com.