Derek the Cuckoo served as the mascot of the short-lived energy drink Irn Bru 32, which was launched in 2006.
He was a giant blue cuckoo with orange hands and hair and spoke with a Glaswegian accent and acted and spoke like a stereotypical Scottish hardman.
He was portrayed by Scottish actor Brian McCardie.
Derek appeared in two adverts. In the first advert, a young man is seen looking bored in a library whilst studying. Just then, Derek bursts through a bookcase shouting "Wakey Wakey" and calls the man a "smart aleck" before giving him a can of Irn Bru 32. Derek tells the man that the drink is pure mental stimulation in a can and that it does not tase like the bottom of his cage. Just then, the librarian appears and tells Derek to shush, only for an annoyed Derek to reply "I'll shush you you tweedy old crow", much to the librarian's surprise. Derek then says "Cuckoo Cuckoo" whilst making hand signals of bring it on at the librarian. Due to complaints about Derek being aggressive, the advert was altered and Derek instead spoke with a posh English accent and spoke politely to the man and librarian. The advert was later reverted back to its original version.
In the second advert, three friends are seen at the bar of a disco looking bored. Just then, Derek bursts through the wall and places an egg on the bar table, which hatches and reveals cans of Irn Bru 32. Derek then tells the disco's DJ to play The Birdie Song.