Oracle Text

(U/R)(U/R), T, Tap two untapped red creatures you control: Crackleburr deals 3 damage to target creature or player.

(U/R)(U/R), Q, Untap two tapped blue creatures you control: Return target creature to its owner's hand. (Q is the untap symbol.)

Card Rulings

8/1/2008 If the permanent is already untapped, you can’t activate its ability. That’s because you can’t pay the “Untap this permanent” cost.
8/1/2008 The “summoning sickness” rule applies to . If a creature with an ability hasn’t been under your control since your most recent turn began, you can’t activate that ability. Ignore this rule if the creature also has haste.
8/1/2008 When you activate an ability, you untap the creature with that ability as a cost. The untap can’t be responded to. (The actual ability can be responded to, of course.)
8/1/2008 To activate either ability, you’ll need Crackleburr plus two other creatures. Crackleburr must have been under your control since your most recent turn began (or have haste), but the other two creatures don’t.