Aliasing cowlick → ahoge
Link to alias

Reason:

The tags ahoge, antenna_hair, and cowlick all appear to mean the same thing based on their wiki descriptions and the way they are tagged.

Personally, I prefer antenna_hair for the descriptive name of the tag (making it easier for users to understand what the tag is used for by the tag's name alone). However, ahoge is shorter to type and is far more populated (ahoge's 1547 posts, compared to antenna_hair's 227 posts and cowlick's 36 posts). Additionally, I could see antenna_hair being mistakenly mistagged for 'character with hair and antenna'.

Tag Alias:

• antenna_hair -> ahoge
• cowlick -> ahoge

EDIT: The tag alias cowlick -> ahoge (forum #275630) has been rejected by @bitWolfy.