Anti-Venom gets stronger the more damage it takes, so with Entangler on it, it can block an unlimited number of creatures and turn all that damage into +1/+1 counters
It has a secondary path of using Erratic Portal, Lava Zombie, and possibly even Palace Siege to get multiple uses out of creatures with good enters-the-battlefield effects, from goad as well as other kinds, most notably Kardur, Doomscourge
For example, Blood Moon changes Dryad Arbor into a Mountain
Red decks are good at creating explosive turns, securing an early advantage, and just generally controlling the pace of the game through disruption, constant pressure, and a bit of calculated chaos
Gaining you 2 life every single turn regardless of the zone its in offers incredible consistency for your lifegain triggers, turning your otherwise mid-tier value creatures into powerhouses
Double strike also means itll make you two Treasures if it isnt blocked