Moo Moo Moo Slot by Playtech

Three cartoon bulls line the left edge, each a coin bank waiting to burst. Grunt is red, Snort green, Huff blue, and every one fills as matching coins drop on the reels. Break a bank and you fall into that colour's feature, so the bull you fill decides the kind of round you get. One of three things opens a bank: three or more Scatters, a Coin of the right colour landing in the base game, or three Hammers, which pick a feature at random on your behalf.

Red is the pick round. Grunt sends you into a wall of red capes that you turn over one at a time, each hiding a Minor, a Major, the Maxi or a plain x2. Keep flipping until three match, and the matching prize pays out at 15x, 50x or the Maxi at 500x your bet. Reveal an x2 somewhere along the way and the whole win doubles, which is the only route up to 1000x. Green is the quiet one. Snort hands over five free games with the royals stripped out, and every green coin that lands carries a +1 that tacks another spin onto the count, no retrigger involved.

Blue does the most work. Huff runs a hold and win on a stretched 5x5 board, and instead of sticky coins you get a Collector Bull that starts as a single cell and stomps around the grid, hoovering up Prize and Crown values as it crosses them. Collect three crowns and the bull swells to 2x2 and earns three more spins; three crowns after that and it fills a 3x3 block with another three spins, covering nine cells and sweeping far more of the board on every move. Prize values run from 0.5x up to the same 15x, 50x and 500x jackpot tiers.

There's no buy button, so every feature has to come to you through the banks filling on their own. Rare Stone built this one for Playtech, and it wears a loud Spanish fiesta: gold-bordered reels over deep purple, roses, teal fans and ribboned guitars glossed up as symbols, a jackpot row glowing across the top, and a laughing golden bull for the Wild, all set inside a sunlit bullring where the crowd tosses confetti down onto the grid.