WAVAX
WAVAX or Wrapped AVAX is an ERC-20 compatible wrapper contract around the AVAX token.
On Avalanche's C-Chain, AVAX is treated just like standard ETH is on Ethereum. This means that AVAX lacks the standardized interfaces that make ERC-20 tokens so interchangeable. WAVAX corrects this by issuing one ERC-20 WAVAX token for each AVAX deposited. Each WAVAX is then redeemable for an equal amount of AVAX.
Implementation
WAVAX is based on the implementation of Canonical WETH developed by the Ethereum community. Details are available here and original source code is available here: https://github.com/gnosis/canonical-weth.
The WAVAX implementation only changes the underlying contract to reflect the new token name of "Wrapped AVAX" and the new symbol "WAVAX."
Security
Because this contract is a fork of canonical WETH, it has the same security characteristics of the Gnosis WETH implementation. That contract has been in circulation for several years and has been thoroughly audited.