Haris Zulfiqar

WordPress tooltip plugins lets you add tooltips to plain text and links on your post and pages.
It offers a tinyMCE shortcode GUI which will guide you through the entire process of a tooltip.
This plugin uses jQuery tipTip authored by Drew Wilson http://code.drewwilson.com/entry/tiptip-jquery-plugin.
You can also add tooltips manually by following the pattern below:
<pre><code>[tooltip content="This will show in a tooltip" url="This will make tooltip a link"]Hover over me for tooltip[/tooltip]
</code></pre>
Url is optional. If URL is added, it will render a link otherwise it will be a plain text.

WordPress Tooltip

WordPress tooltip lets you add tooltips to content on your posts and pages.

rustybroomhandle

Easily turn links to Minecraft items into fancy pop-out tooltips. Simply link to the relevant item’s page on http://www.minecraftwb.com/ and the script will do the rest.
Caches data locally to minimise data transfer.
Will eventually add the ability to link by item name through a shortcode, like [mcwb:Diamond Pick] or similar.

Minecraft Workbench Item Tooltips

Easily turn links to Minecraft items into fancy pop-out tooltips.

WordPress Tooltip vs Minecraft Workbench Item Tooltips