Krypto the Super-Dog is seen as a white, medium-sized dog that wears a red cape with a 'super S' symbol on it and a yellow collar. He (Superman encourages him with "good boy") is Superman's pet and can be kept at the Fortress of Solitude for guard duty where he will respond to a whistle from his owner. He will also obey the commands of other members of the Justice League when he is left on duty at the Watchtower.
The powers of Krypto are similar to Superman's as we see he can fly and he has sufficient super-strength and invulnerability to survive being buried by a heavy rock fall and digging himself out afterwards. His main offensive power is his heat vision which he uses frequently. The pendant on his collar can send out a signal when it is bitten which can alert at least Streaky if not the whole Justice League.
In the rare event that Krypto misbehaves, he can be sent to the Watchtower's sun room to be bathed in red sun radiation to restrain him.
- Krypto at Wikipedia.