Sadly this is way too cheap. You get free ": " for 3 mana (Minister of Impediments), or 4 if you want to untap also (Fatestitcher). You can get to untap also at 3 mana if you pay 1 to activate (Puppeteer). Down at 2 mana you need to pay 2 mana to activate if you're untapping (Stonybrook Angler), or just 1 if you're only tapping (not been done in blue, but Master Decoy etc in white).
So since we don't want this to untap things, it could be for a 1/1 with activation cost; or for a 1/1 with no activation cost. Or possibly for a 1/1 with activation cost.
: Tap target creature.
Sadly this is way too cheap. You get free "
: 
" for 3 mana (Minister of Impediments), or 4 if you want to untap also (Fatestitcher). You can get to untap also at 3 mana if you pay 1 to activate (Puppeteer). Down at 2 mana you need to pay 2 mana to activate if you're untapping (Stonybrook Angler), or just 1 if you're only tapping (not been done in blue, but Master Decoy etc in white).
So since we don't want this to untap things, it could be
for a 1/1 with 
activation cost; or 
for a 1/1 with no activation cost. Or possibly 
for a 1/1 with 
activation cost.
fix costs