If I create a trigger with
COMMENT = 'Wonderful table with users inside';
You cannot attach a comment to a trigger.
You can however put comments in the trigger body.
If you type the in body comments like
/** comment **/
You can extract these comments with the following query:
SELECT SUBSTRING(b.body, b.start, (b.eind - b.start)) as comment FROM ( SELECT a.body ,locate('/**',a.body) as start ,locate('**/',a.body) as eind FROM ( SELECT t.ACTION_STATEMENT as body FROM information_schema.triggers t WHERE t.TRIGGER_NAME like %aname% ) a ) b